[1.16.1] Calling Gl.capabilities for custom block renderer

I'm rendering a custom block using openGL, and to do this I am calling Gl.capabilities in order to setup a framebuffer. In 1.12 I had called this during the client FMLPostInitialization event, but this no longer exists. I cannot call it during the FMLClientSetupEvent because it needs to run after vanilla Minecraft has run GL.createcapabilities on the main thread. Any suggestions as to when/where I can call this in order to setup my frame buffer?

Error given when calling the Gl.createcapabilities method on FMLClientSetupEvent:

[19:56:40] [modloading-worker-3/ERROR] [ne.mi.fm.ja.FMLModContainer/]: Exception caught during firing event: No GLCapabilities instance set for the current thread. Possible solutions:
	a) Call GL.createCapabilities() after making a context current in the current thread.
	b) Call GL.setCapabilities() if a GLCapabilities instance already exists for the current context.
	Index: 1
	Listeners:
		0: NORMAL
		1: ASM: class com.mymod.main.event.EventSubscriberClient onFMLClientSetup(Lnet/minecraftforge/fml/event/lifecycle/FMLClientSetupEvent;)V
java.lang.IllegalStateException: No GLCapabilities instance set for the current thread. Possible solutions:
	a) Call GL.createCapabilities() after making a context current in the current thread.
	b) Call GL.setCapabilities() if a GLCapabilities instance already exists for the current context.