Everyone I spoke with said they could not/would not refinance a duplex with an ADU as it would make the loan intelligible to be packaged and resold...or something along those lines. 

A basic GE stainless steel kitchen package runs around $2,500

Lately we are packaging a cutting board with two plastic champagne glasses and sparkling water.

Maybe you can try to talk to those lender's bosses to see if they know of a product, or find a lender that's willing to work with you to tailor a loan solution to you instead of trying to sell pre-packaged loans.

I have a realtor I use and a few different lenders that offer different packages that I can work with.

As a PRO member, you have free access to the Biggerpockets Lease Agreement Package under "TOOLS" at the top of your screen.

I am looking to buy an off market duplex in my area and am contemplating trying to package a couple houses together as the collateral for a portfolio loan.

You can close the transaction remotely via a Fed-Ex package or other overnight carrier, or perhaps a mobile notary or equivalent (maybe a bank where you reside?)

The investor did this to buy say 5 properties with 20k and get a low offer accepted instead of 1 with 100k.Banks caught on and many have clauses that if a cash offer is changed to financing then earnest money becomes non-refundable and the bank (seller) reserves the right to terminate the contract at their discretion.

While many entrepreneurs start with a software package or template to cover the basics, be sure the plan works for you and meets your needs.