Some answers from me
If the board is released I will try to support it. (Will not spend time on before this.)
The differnces between CF and 68k seems to be large. Often used Opcodes and Adressing Modes are dropped. I think this will have an serious impact on performance. Also many apps/games running under WHDLoad have their stack in chipmem this will degrade emulation performance. The VBR at 1MB boundary is annoying, but workaround should be possible.
Single stack in CF may cause incompatibilites which may require install adaptions.
The emulation of unsupported instructions and addressing modes should work as current with the 68060 ones. I think the CK68KLib will do this. The WHDLoad core will need adaptions tough.
Using the 5475.library I would like to avoid because it would be incompatible with using MMU exclusive by WHDLoad (as it current is).
MMU support of the CF will be probably possible. I have not yet checked which functions the CF-MMU provides or what the differences to a 68040/60 are.
So, first the hardware must be out then we will see further