Is there any reason why you don’t want to move into the new duplex for the next year in order to get lower lifetime interest rate, lower downpayment, etc.?

I would invest the extracted money into something that is expected to have far better return than my loan over the long term (even S&p500 has lifetime return over 9%).

For example, I've been putting 3.625$, now it seems like it is only in increments of 2,3,4,5 percent.

save 10 percent. 

Since I'm exceedingly selective upfront because I intend to hold all my stocks indefinitely my losses have been very few and far between.3) All the capital appreciation on my stocks will be wiped out in my estate so my lifetime taxes paid will be negligible.4) A Roth works too, however I don't qualify and conversion of my regular IRA would be tax cost prohibitive.5) All my current and future cash needs are funded from RE portfolio and work.

I have seen two separate appraisers go to the same property, in the same condition, and both come back almost 40% apart on the value, but when it comes to banks needing some type of proof of value, and the fact that most people only buy one or two homes in their lifetime, they just want someone to be able to tell them they are not overpaying.

I don't see it happening in my lifetime. 

I would say it's a great way to guarantee a long-term stable renter with a partially guaranteed (I've seen up to 80 percent) rental payment.

I'm sure many of you can remember the Global Financial Crisis that occurred between 2007 and 2009 due to the government’s encouragement of broad homeownership induced banks to lower their rates and lending requirements,5 which spurred a home-buying frenzy that drove the median sales price of homes up by 55 percent from 2000 to 2007.BAs a result, Banks were handing out loans like candy to anyone and everyone, combined with the explosion of the United States run-up in housing prices fueled by demand, speculation, and exuberant spending to the point of collapse.This crisis damaged financial institutions globally which led to a loss of more than $2 Trillion from the global economy! 

A record 22,114 new jobs were attributed to businesses either expanding in Austin or moving to the city in 2020, compared with 13,562 in 2019, the chamber said.Nationwide, office vacancy rates rose to 17.1 percent by the end of 2020, the third consecutive quarterly increase, according to a report released in January by JLL, a commercial real estate services company.