What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

  -  All of the homes/properties have been renovated and have been in service for a number of years (meaning we have a strong history as successful  property owners/investors)-  All of the homes are higher-end rentals in very good neighborhoods -  All but 4 homes are completely paid off  with no mortgage overhead or LOC debt-  All homes have a very consistent rental history with very low vacancy-  All homes are turning a profit and our pre-door numbers are very goodBecause the homes are almost completely paid off, we have a good deal of equity in just sitting around. 

These will still require a decent credit score and at least 25% down payment.  

.), plays a big role.Generally, there are three main refinance options for BRRRR method investors: Conventional loansBank/credit union loansDSCR loansConventional loans are generally defined as loans originated under GSE (Fannie Mae/Freddie Mac) rules and guidelines and securitized.

Also, do you have any 0% interest credit card offers that could help fund/pay the roofers in the meantime?

You can probably get a line of credit for your business and use that if you don't want to front the costs.

Age or properties, appraisals, past credit and business experience could also play a role.

But what if he has a drug history?

What are the most promising alternative lending strategies for financing RE developments given the rising interest rates and tightening credit conditions?

Secure a credit facility with a Hedgefund or bank and lend that money out..