There is no such thing as a simple “pod” – quite some things need to be ’emulated’ when replacing a 030 by an 040. Just have a look at the accelerators used for the 68k Macs or Commodore AMIGA. They have quite some logic added and need at least patches for the 68881/2 emulation.

Speaking of FPU – your game system (chess?) probably does not use an FPU and maybe its code is extremely optimized for the 256byte caches of the 030 and/or is critical to execution times. So my assumption is that such a stunt would include quite an amount of software patching, too.

In my view, a more feasible approach would be overclocking. Good 030’s can be overclocked to 50+MHz – depending on the rest of the system (RAM/ROM) this might work.
I know of Mephisto chess modules (68020) which were overclockable from 16 to 22.5MHz.

Cheers, Axel