Possible to "augment" an existing HM generation with a flake?

I just had a funky idea for the following use case:

Suppose you wanted to “distribute” your service as a flake with a user systemd unit definition.
Now it would be cool if one could simply call/execute the flake as (any) HM user and have it execute the necessary HM config steps (from the flake) and activation(s) as a user service.

If it would really need to hook in to the existing HM config (which is a fixed link farm per generation?) one would maybe need to

  • get the currently active homeConfigurations attribute
  • “augment” it with the flake under execution (ideally in the flake it would say something like home.services..... = ...)
  • rebuild and reactivate the new (= original full HM config + flake definitions) config

This would basically embody a “medium temporary” install, that would be overwritten when a normal HM config rebuild is done. Something between a full re-config and nix-shell

This could also constitute an intermediate step to test new HM modules to be added to HM later.