I would hope that the most they’d do is limit/throttle the number of new and updated issues. As long as the limit is very generous for a normal project, this sort of thing would still be supported at reasonable usage levels.

Hopefully it wouldn’t be considered abuse just by its nature (as opposed to any traffic spikes it might cause). Quite the reverse, this shows off the flexibility of the service!

This is definitely just a fun hack and not meant for production! For production ready short links with low overheads I would personally recommend using Firebase URLs or cloud firestore.