This would be so useful!

Is there an ETA on this feature? I'm reluctant to move over from YNAB until it's available but v eager to!

If implemented, this will also tie to manual transaction entry on synced accounts, where the manual entry would "link" with the synced entry. This is something many other financial apps can do.

Just in case someone else finds it useful, I've put together a GitHub Action which solves this problem space for my purposes (linking transfers between accounts and associating "spare change" transfers with a purchase).

The documentation (especially as it relates to the rules you configure in Lunch Money) needs some work - but you should be able to infer the gaps based on what's there.

See https://feedback.lunchmoney.app/rules/p/use-rules-to-auto-group-transactions