This is a commercial product so it's not _quite_ what you asked for, but the production volume is pretty low (100s) and the implementation is literally an FPGA dev board mounted to the back of the interface panel.

https://intellijel.com/shop/eurorack/cylonix-rainmaker/

In this module, the FPGA's ability to do LOTS of computations in parallel is used to produce 16 taps of pitch-shiftable delay along with a 64-tap comb filter.