Environment maps in ebony cuirass and HiRez Armors Indoril cuirass don't work
MCP bump maps support was added with https://github.com/OpenMW/openmw/pull/2714.
Testing HiREz Armors (https://www.nexusmods.com/morrowind/mods/47919) I've found that only on OpenMW the cuirasses don't have that metalic effect.
Linux Mint 64 bits
Daily 0.45.0+git202005121534~ubuntu18.04.1