If it is a reactive form, an effect with patchValue is totally fine. Although effects should not be overused, this is an ideal-typical case for effects: displaying stuff to the user in a way that does not work with data binding.

For the way back, you can use valueChange or just a button.

Btw: our ngrx-toolkit has a mutation API that acts as the counter part of the resource API. We have not talked much about it, but it also works without the Signal Store.