What I'd add onto that is that it depends on how much cash out you're going to get from refinancing and what you can reinvest those cash out proceeds into once you have them.

With this type of structure, as soon as you are done with the work completed, you submit the budget for the purpose of rationalizing the massive increase in value in a short period of time rather than leveraging it in an LTC calculation that will cap your cash out proceeds.

You will need to pay the agent a commission, which can drastically eat into your cash proceeds on a flip.

The str will close before the land sells and then I would like to recast the loan to pay off a portion with the land proceeds.  

The best option is to proceed with a cash-out refinance utilizing a DSCR loan. you can grab up to 75%LTV all by using the current tenant's lease agreements to cover the debt service requirement.

debt coverage is a greater obstacle...than appraisal at 75-80% LTV" - 100% agree...DSC is determining loan proceeds in this high rate environment, not LTV.

It's crucial to address these before proceeding.

They manage their business full timeI’m any case, good luck in whatever way you decide to proceed  

He purchases a duplex primary home this year and in 1-1.5 years he purchases a nicer larger 2-4 unit, maybe in a more desirable area – that would make sense and generally get approved with primary home financing assuming of course he was going to occupy a unit.The whole strategy he plans to employ requires a “move-up” each new purchase and he already has a SFH which causes a big hurdle in the “move-up” strategy so once again selling that would behoove him.The plan he didn’t mention which is really the only plan that will work in the short term is:Sell current primary homePurchase owner occupied 2-4 unit with 5% downPurchase additional; 2-4 units with 25% down with the remaining proceeds from sale of primaryI am happy to make an introduction to Richard if you would like to discuss further.

Make sure you get a "Release Fee" on each property; this is an amount that is to be paid to release a property as collateral in the event you need to sell, or if you have an insurance loss that insurance proceeds will be applied to the subject property and not to the whole loan keeping you stuck with an encumbered damaged property, remember they don't make construction loans as a second and the blanket loan won't subordinate (usually) to another lender, it could get messy, so have a release fee stated and understand how payments will be applied.A line of credit is not a blanket mortgage but a line of credit can use other collateral, different animal and it may or may not fit you needs.