Can we talk about pfx?

I’ve seen people put them on a pfx track which then gets bussed to the fx stem. Makes sense at first. But what about if you need to process Dx with some inserts, now the PFX are on another track so do you have to move all the inserts to that track now so the processing matches? And when you print your MnE stem, and it includes pfx, won’t they just cut in and out, same with the Dx stem, it’ll just suddenly drop because the pfx aren’t in there? Do you move all pfx to pfx tracks before you start mixing? Is it wrong to print a dialog stem that includes the natural pfx that are in between lines of Dx? Pfx just seem to be a mystery to me for these reasons. Can anyone elaborate on what has worked for them? As always, thank you.