Ah, I had completely forgotten about the demos in the test folders, thanks!
In the meantime I already went through all the demos on the demo repo... I'll log the results here anyway for future reference for others trying to run them? Although I realize most of them are just issues with OpenGL on macOS. I only just started work on programming again, and very disappointed to find a 1 year old laptop supports only a 7 year old API ie. OpenGL 4.1
Thanks for the tips!
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.UniformArrayDemo - NSGL: The targeted version of macOS does not support OpenGL 3.0 or 3.1 but may support 3.2 and above
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.SimpleDrawElements - works
assimp
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.assimp.WavefrontObjDemo - java.lang.IllegalStateException: Unable to open file "/Users/peter/Downloads/lwjgl3-demos-master/file:/Users/peter/Downloads/lwjgl3-demos-master/target/lwjgl3-demos.jar!/org/lwjgl/demo/opengl/assimp/magnet.obj".
fbo
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.fbo.DepthEdgeShaderDemo20 - works
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.fbo.EdgeShaderDemo20 - works
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.fbo.EdgeShaderMultisampleDemo20 - works but red bars in background
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.fbo.MultisampledFbo2Demo - works
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.fbo.MultisampledFboDemo - works
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.fbo.ReadDepthBufferDemo - works
geometry
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.geometry.GeometryShaderTest - works
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.geometry.GeometryShaderTest20 - works
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.geometry.SilhouetteDemo - works
glfw
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.glfw.Multithreaded - works
instancing
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.instancing.GrassDemo - java.lang.UnsupportedOperationException: ARB_vertex_array_object is not available
raytracing
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.AtomicDemo - Requested OpenGL version 4.3, got version 4.1
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.Demo - Requested OpenGL version 4.3, got version 4.1
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.Demo20 - ERROR: No definition of randomHemisphereCosineWeightedPoint in fragment shader
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.Demo33 - works
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.Demo33Ubo - works
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.DemoSsbo - Requested OpenGL version 4.3, got version 4.1
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.DemoSsboTrianglesStacklessKdTree - Requested OpenGL version 4.3, got version 4.1
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.HybridDemo - "
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.HybridDemoSsbo - "
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.HybridDemoSsboInstancing - "
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.HybridDemoSsboInstancing45 - Requested OpenGL version 4.5, got version 4.1
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.HybridDemoSsboTriangles - Requested OpenGL version 4.3, got version 4.1
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.PhotonMappingBindlessDemo - "
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.PhotonMappingDemo - "
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.raytracing.TransformFeedbackDemo - "
shader
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.shader.ImmediateModeDemo
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.shader.NoVerticesBSplineDemo - NSGL: The targeted version of macOS does not support OpenGL 3.0 or 3.1 but may support 3.2 and above
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.shader.NoVerticesGridDemo - "
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.shader.NoVerticesPolygonDemo - "
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.shader.NoVerticesProjectedGridDemo - "
shadow
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.shadow.ShadowMappingDemo - NSGL: The targeted version of macOS does not support OpenGL 3.0 or 3.1 but may support 3.2 and above
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.shadow.ShadowMappingDemo20 - works
swt
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.swt.SwtAndGlfwDemo - objc[7404]: Invalid or prematurely-freed autorelease pool 0x7f901f813b50. Set a breakpoint on objc_autoreleasePoolInvalid to debug. Proceeding anyway because the app is old (SDK version 10.9.0). Memory errors are likely.
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.swt.SwtDemo - works
textures
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.textures.BillboardCubemapDemo - works
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.textures.EnvironmentDemo - works
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.textures.EnvironmentTeapotDemo - works
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.textures.FullscreenCubemapDemo - works but not fullscreen
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.textures.SimpleProceduralTextureDemo - works
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.textures.SimpleTexturedQuad - java.lang.NullPointerException, at org.lwjgl.glfw.GLFW.nglfwSetKeyCallback(GLFW.java:3483)
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.opengl.textures.Texture2DArrayMipmapping - NSGL: The targeted version of macOS does not support OpenGL 3.0 or 3.1 but may support 3.2 and above
org.lwjgl.demo.intro.Intro2 - demo 2,3,4 has a crazy flickering between blackj and red backgrounds
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.bgfx.Bump - works, but full screen is partially off screen
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.bgfx.Cubes - works, but full screen is partially off screen
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.bgfx.Metaballs - works, but full screen is partially off screen
java -XstartOnFirstThread -cp target/lwjgl3-demos.jar org.lwjgl.demo.bgfx.Raymarch - works, but full screen is partially off screen