Yes you can definitely qualify for the STR loophole if you materially participate and keep the average rental period at 7 days or less. 

For the remodel I am thinking of extending the main home (which would make it "L" shaped") to incorporate the detached carport and detached bedroom/bathroom.  

The rates and terms are usually more favorable than DSCR loans, so I’d lean toward conventional financing while you can still qualify.BRRRR Method: The BRRRR strategy can be powerful, but it might slow you down a bit due to the current cash-out refinance seasoning periods, which can be as long as 12 months.

Your activity isn’t a rental activity if any of the following apply.The average period of customer use of the property is 7 days or less.

I think it is, but it is not the same BRRRR method investors are used to.The Changing Real Estate LandscapeThe real estate market has fundamentally shifted since the period from 2017-2020, which was marked by relative stability in terms of interest rates, demand, and supply.

This waiting period helps ensure that the loan meets their guidelines and reduces risk for the lender.

Or, if possible, sell them (but I'm guessing that selling the units to owner occupants is probably not allowed and that they must remain rentals for the 30 year period). 

At least not over an extended period of time.

I recently put two new clients from BP in their first ever bridge loans for a fix and flip in my PA network and they bought for like 180k and I got them 90% financing and between the downpayment, closing costs, holding costs and fronting the GC I partner with the deposit they will need to extend like 45k - 55k to see through a 5 month project where they will net about 30k - 40k after all taxes and expenses. 

EXTENDED CLOSING DATE  - extend the closing to 59 days before expiration of one of the leases.3.