If not the borrower is in default, probably given some deadline to cure and subject to foreclosure.Perhaps a borrower could arrange a payment plan to stretch it out over a couple of years...but I don't think it would be over 15-30 years.All of this is pure speculation on my part.....probably the best person to ask would be a servicer, but that might be easier said than done. 

Do I have to allow the tenant to cure their default?

I believe they will continue to make an issue of the duct cleaning, claiming that it is necessary to cure their "allergies" (I don't believe they have allergies).

I personally love deposits as most of my units are in the burbs (where the law still gives us a right to cure).

I also read The Tax Cure.

Interesting.I've had some properties where the Buyers seemed to value it the same as permitted, or as an Appraiser, I might give it a value similar to legal gla and just adjust for a "cost to cure," to represent what it might take to get it permitted.

((is there some "seller financing" class going on that is telling people its the magic cure-all for everything going on??))

I'm considering a "Notice to Cure", but I'm concerned that since I did not actually see the animal, the tenant can just concoct a story about how he was "watching" a friend's cat (a violation, nonetheless) but that he's gone now. 

First you usually post notice to cure (ie pay up or else), then start with the eviction. 

You may need to have an abstractor run the chain of title via grantor/grantee and see if somewhere in the back chain a transposition error occurred that might be able to be cured.