Thanks for the replies.
I found it ---
/script SetCVar("LuaMemoryLimitMB", "2048")
But it is not curing my current UI Error problem. Harvest Map seems to be the current problem.
Like i said above, that cvar has been deprecated for a while now, it doesn't work anymore.
ZOS redid the way LUA memory is handled in-game, there is no need to set the limits manually anymore, it's all dynamic now, hence why that cvar was removed.