MCP, BlazeWCP, fblit, ftext modify major system functions and can conflict with one another. Back in the day I spent ages with them, I've forgotten more than I remember but there is a lot of guess work in order to get a stable system when patching things like this. Thats the trade off for a faster system.
In the end I actually wanted my A1200 to work without feeling I'm playing Russian roulette, and I just used the latest 060 library and the HSmathslibs, with reduce colors and resolutions.