I can now reproduce this locally, and expect to have a fix this evening. I've looked over the rules for the Soft Freeze, and understand that it'll be acceptable to cut a new upstream release (I'm the upstream author) with this fix only (there have been no other changes since this release), upload that to unstable, and let it proceed (possibly slowly) to testing.
If I instead need to make a debian-specific patch against 1.2.28-1, and release it as 1.2.28-2, that's also fine.
