I'd noticed this a few days ago too as it seemed to have fixed an issue they'd had previously with the Facebook URL they displayed in the admin interface that didn't work, but was different from the URL that Syndication Links picked up. I mostly noticed because when using the SNAP buttons after initial publication they give modals showing success in posting which include the returned URLs, which for some silos can make it easier to cut and paste if necessary.

Your solution sounds like a sound one.

Your other thought recently about storing the URLs separately from SNAP's store is a good one as well because I've noticed (and generally not cared, though others surely may/will) that if one re-syndicates a post with SNAP, it overwrites the prior URL with the new one, which means that Syndication Links wouldn't have a "complete" list of all POSSE copies. This also means that Bridgy will only return replies on the most recent one for each silo this is done in. Anyone using SNAP's scheduling feature will be losing some of their backfeed as a result.