Sounds workable, though you'd also need a way to save and restore any internal state, or else some way to mark off checkpoints where it is interruptible.

The other thing to note is that this only covers using the FPGA for compute. While that's the obvious use-case for an "FPGA in CPU" concept, in the real world, IO is a pretty important part of many non-cryptocurrency FPGA applications, whether you're just counting edges on some input like an encoder, providing a highly time-sensitive output signal, such as for an SDR, or implementing some custom serial protocol.