I think I've found a bug that's indirectly caused by the time scaling in this mod.
The health of the Cims crashes after a few years in game regardless of health coverage. Removing this mod corrects the issue; everyone dies from being 200 years old, new households move in, city health improves to 80% and holds.
I have a gut feeling that the Cim Health calculation is overvaluing the age value, or the age value it self is higher than what was intended.
I hope this helps; this and your other mods are great and appreciate the work you put in.