The due on sale clause simply gives the lender the RIGHT to call the loan due upon transfer of title.The exceptions to calling the loan due in the Garn St Germain Act are below....See http://www.law.cornell.edu/uscode/text/12/1701j-3(d)Exemption of specified transfers or dispositions With respect to a real property loan secured by a lien on residential real property containing less than five dwelling units, including a lien on the stock allocated to a dwelling unit in a cooperative housing corporation, or on a residential manufactured home, a lender may not exercise its option pursuant to a due-on-sale clause upon—(1) the creation of a lien or other encumbrance subordinate to the lender’s security instrument which does not relate to a transfer of rights of occupancy in the property;(2) the creation of a purchase money security interest for household appliances;(3) a transfer by devise, descent, or operation of law on the death of a joint tenant or tenant by the entirety;(4) the granting of a leasehold interest of three years or less not containing an option to purchase;(5) a transfer to a relative resulting from the death of a borrower;(6) a transfer where the spouse or children of the borrower become an owner of the property;(7) a transfer resulting from a decree of a dissolution of marriage, legal separation agreement, or from an incidental property settlement agreement, by which the spouse of the borrower becomes an owner of the property;(8) a transfer into an inter vivos trust in which the borrower is and remains a beneficiary and which does not relate to a transfer of rights of occupancy in the property; or(9) any other transfer or disposition described in regulations prescribed by the FederalHome Loan Bank Board.

CODE:(1) the term “due-on-sale clause” means a contract provision which authorizes a lender, AT ITS OPTION, to declare due and payable sums secured by the lender’s security instrument if all or any part of the property, or an interest therein, securing the real property loan is sold or transferred without the lender’s prior written consent; Please note: "AT ITS OPTION"

What do I show to the new 1st lender prior to-or at closing to show what skin I have in the game (instrument such as a letter, a promissory note).

Has anyone used a automated phone system for this purpose?

Then I send an automated email campaign that attempts to get them to follow up with me and to set an appointment with them. 

@Jack Moreno, @Addison Guyse The maximum DTI allowed for conventional loans is typically 50% and FHA will allow up to 56.99% with automated underwriting approval. 

to the extent the instrument of transfer vesting the Title as shown in Schedule A is not a transfer made as a contemporaneous exchange for new value; orii.

Automating your cleanliness process is key.

Consider using tools or software for property management that can help to automate the procedure.In the Bronx, become familiar with the zoning and leasing restrictions.

Learn to automate it as much as possible for the least amount of expense.