I may be misunderstanding your question.In an "assumption" (it's an actual banking term with a definition) the bank takes you though the same hoops as if it's a new loan.

Is there a loan assumption available?  

While trying it out, call their customer service and see how they treat you and how knowledgeable they are on their product.

Brandon Turner's Rental Property Investing book is an excellent primer to understanding the happy path for purchasing a property - however in this market it really comes down to having bulletproof assumptions on rents/taxes/R&M/etc. as with rates as high as they are/inventory as low as it is, there is less cushion in your returns if you analyze properties with bad assumptions.

I do see lots of self storage and warehouses going up, so my default assumption would be that the old shopping malls do NOT trade for less than build cost, but it's possible that the marketplace is not perfectly efficient. 

Would love to hear your thoughts on whether pursuing this adjustment makes sense or if I should reconsider.For reference, I’ve included the following assumptions in my calculations:5% for maintenance3.5% for vacancy10% for capital expenditures and management feesThanks! 

I'm currently working with a lender that has a $50k minimum, and his rates and customer service have been great so far.

Additional Info —Key Details:Location: Outside Santa Fe, NMProperty Size: 20 acres (valued at $80,000)Project: Two new STR unitsExisting Experience: Family has two fully-occupied LTRs nearby, generating $2,000/monthConstruction Approach: Self-contracted with licensed trades for electrical/plumbingCost Assumption: $80,000 per unit, plus ~20% for inflation (based on 5–8-year-old build costs)Financing: Using land equity as down payment on construction loan (expecting closing costs to be major expense)Request: Looking for feedback, potential pitfalls, and general guidance

I don’t need help often but have had good luck with customer service when needed.  

If you're anything like me, customer service is the main draw for me when I am choosing any service provider.Look at websites, reviews and testimonials.