We have a few objects where refmt serialization is the bottleneck in our app... taking up to 1ms to serialize an object.

I'm wondering if it's possible to specify a fast-path for these objects... here it seems to say I might be able to have my own machine:

 For the most esoteric needs, you can fall all the way back to providing a custom MarshalMachine
     (but avoid that; it's a lot of work, and one of these other transform methods should suffic

However, the MarshalMachine interface has unexported type expectations in the fields.

Any other suggestions for keeping refmt around but being able to register my own "fast-path" ?