When using some shaders all textures become black. So far I've only found Sildurs extreme VL and BSL to cause this and BSL only seems to cause it occasionally while holding a placeable item like blocks or flowers.

This is not necessarily an issue with BetterEnd. Slidurs are not suggested with this mod as they are know to have some problem on their side. I haven't personally tried with BSL. You could try with Chocapik shaders, they should work very well