There is an acceleration clause is most deed of trusts, that is, his mortgage document that calls for a full payment of a mortgage if the title is transferred in this manner, but people do it all the time and accept that is the mortgagee/lender ever exercises this clause then you'll just have to refinance the property and since you were paying the mortgage and have proof, you should have no difficulty in refinancing the property. 

Partnerships (active and passive) are another option (exercise the usual precautions).That's all I know at this point. 

I would not count on them exercising the option, especially considering the state of the lending industry.

Once that is done you can exercise your option to purchase or sell the option to a new buyer for quick cash. 3.Get seller financing.

Would this be an exercise in vain trying to pursue this with my lender?

However, this option shall not be exercised by Lender if such exercise is prohibited by Applicable Law."

It was a 5yr lease  with (3) 5 year extensions that we exercised. 

I hope it's helpful as a thought exercise at least.

A 1031 is definitely not a do-it yourself exercise. 

So subject to has some risk, but as long as the bank is getting paid, the chances of them stepping in and exercising any due on sale clauses is very low.