Hello, I am happy to assist you today.
There is definitely a big difference between the bank's statute of limitations to pursue an action on the promissory note, and your ability to purchase either property with a clean title that has not mortgage attached.
First, keep in mind that the promissory note itself does not bind the property. The mortgage document binds the property securing it for the note. So the actual note itself is merely a personal debt that is unsecured but for the mortgage document.
If the banks decide not to pursue those borrowers for longer than the statute of limitations (which I believe would be 3 years, I haven't seen the 36 month rule you refer to), then the borrowers would certainly have a claim against those banks to request a release of the mortgage so that the title is clear. The borrower would do the title clearing action.
If you choose to purchase the properties with the mortgages still on record, then be aware that you also are bound by those liens in the event that you can't get them off the title. It would be a risk. You may be able to do it, but it would be much safer to have the borrower go through that process first, rather then wait until after purchase.
Let me know if you have any questions about this.