(Locally) how to apply an updated subflow over multiple machines?

Yeah, I probably have asked before.

I have just had a lot of fun retrospectively rolling out an update of a subflow I wrote over my machines.

Is there an easier way?

I had to copy/export the new code, go to each machine, edit the subflow and paste in the new code and hook it up.

Not the worst but a bit tedious.

Keeping things LOCAL...

Is there an easier way?
(Oh and keeping it simple.)
If it involves too much stuff, it may not be easy for me.