Keep in mind that when refinancing, you need to do a cost/benefit analysis and take into consideration the higher mortgage and monthly payments.

I'd give more consideration to the end user interface... the devices, how well the rooms heat up, air flow, and thermostat controls.

The cost of a good "quality" cost seg study has come down considerably in the last few years. 

House prices dropping, rentals slowing, and construction prices rising...

I'd also recommend reading David Greene's book on BRRRR investing as it goes over in much more detail the different lending options and considerations for BRRRR.

I always ask my set of questions for vetting a lender, but since this lender is a bit different I wanted to ask the community what are some considerations to look out for and some good questions to ask?

But a key consideration is having cash reserves after the down payment too.

When getting pre-approved, are there any considerations when shopping approval & interest rates from different lenders?

Then, once the equity doubles (pus closing costs) my DP, I sell, I move my equity forward before I lose too much money with the rising equity.

I started typing up a lengthy post to outline all the considerations when building two houses on a single parcel ... but then I aborted the effort.