Hi!
that makes sense. It sounds like in the short term (and until we have a Wikimedia-operated shortener), using full URLs from WDQS is – alas – the only way to go. One option we haven't mentioned would be for WDQS itself to support URL shortening, I have no idea where that would sit in terms of priorities.
I don't think it'd be very high. It would require building infrastructure that Wiki extension already has, and for sole purpose of implementing functionality that is already provided by that extension. So I think the best way here is just to wait until it's deployed, and maybe gently prod responsible people from time to time :)