And I still won't, because nobody would read it, just like I think almost nobody actually read carefully my three longer posts; they just skimmed them. That's why we get semi-nonsensical answers.
Hey I caught this part at least.
I don't know what I said in the past. I will say new things.
I am going to say this without using the terminology, because I don't want definitions of terminology to stand in the way of communicating functionality. It may be that all you care about is those definitions, but, I am explaining this interaction, not defining terms.
Normally when you play an Action card it does some stuff. It may also have stuff it does at other times, like Moat's reaction or Highway's while-in-play; we aren't concerned with those now but I haven't forgotten that they might be there. Anyway. You play an Action card, it does some stuff.
Enchantress says, don't do that stuff, for this one card played this one time, instead +1 Card +1 Action. The card is otherwise unaffected. The playing of the card is otherwise unaffected.
Royal Carriage says, after you're done dealing with having played an Action card, not meaning you're done with stuff like calling Royal Carriage ha ha, you get a chance to call this and well you know, what Royal Carriage does. I mean Royal Carriage isn't necessary here, it's exactly the same for Coin of the Realm.
Maybe someone is thinking, but Enchantress changed what the card did so the card never did it so Royal Carriage can't be called. No. That's not what happens. Royal Carriage doesn't say "At the point at which you'd be done following those instructions if only you'd followed those instructions" or "after you follow the instructions or do some other crazy thing like Enchantress," but that's okay, that game is unplayable.
"In-between Action plays" is a hard-to-phrase concept. I was not happy with the phrasing on Royal Carriage, changed it for the new printings, and still it seems like it could be better. I am not putting in the work here today but note that Citadel has a similar timing and yet a much different phrasing.