It looks like with the granular downscaling changes, the regular lower_threshold settings aren't checked properly. This fixes it for me, not sure if there are other places in the project to check.
Fix the lower_threshold checking
I think those are the only changes that need to be made. Sorry about the error!
Thanks @KyleAlanDavis for the fix and thanks @Sazpaimon for verification. It has been pushed to PyPI now with version 2.1.2.