- Elder only interacts with "choose N."
Scrap says "choose a different thing", not "choose N", but close enough I guess.
My understanding of Scrap is that it's worded the way it is to save a few words (and probably a line, and maintain a large enough font size). It could read "Trash a card. For each $ it costs, choose 1: ...; ...; ... (the choices must be different)." Then it makes the wording very similar to Courtier, and now has the "choose N" trigger.
This is true, but the question comes down to when does a choice of wording made to save space also then end up having a rules impact? Cards like Envoy received errata so that the "draw" text didn't interfere with new stuff that cards about drawing (-1 card token). Envoy, both old and new wording, don't interact with Way of the Chameleon, even though you could say that Envoy's wording was just a clearer version of "Discard that one. +4 cards".
Capitalism, Way of the Chameleon, Patron, and now Elder all care about not only what sort of ability a card has, but what specific wording is used on the cards to deal with that ability.
We know that Elder is intended to work with Scrap's wording, and that it's not intended to work with
Navigator's wording (even though Navigator could have just as easily be written with a "Choose one" wording instead). But we don't know an exact rule (yet) for what set of words makes Elder work. Sounds like it has it must have the word "choose", and also must list a series of effects that you can choose from afterwards.