While private money isn't highly regulated at the federal level, there are subtle nuances to be aware of in each state that may trigger your loan becoming a security and then the SEC would have regulations to consider.

However, I’ve take five 401k loans up to 50k to buy houses.

There are closing costs, loan origination fees and Homeowner's Insurance to add into the number, You will get better detail from whomever is lending the money.

Loan to value ratio: The higher the loan to value ratio (LTV) is, pricing takes a hit.

It’s combining the inflation numbers with the higher cost of credit/borrowing.

Loan to value ratio: The higher the loan to value ratio (LTV) is, pricing takes a hit.

Try playing around with the loan amount to see what amount provides you the best combination of getting your money out but still getting a good return on your investment. 

Does the IRS care about the type of loan I'm using?

I had planned to take out loans in a cashout loan but rates accelerated too fast in 2022 and I never got that chance.But now that everyone is talking rate cuts I’m kinda thinking I take the deal and hope I can refinance these 2 properties at 5% interest (or less) sometime before 2028?

They are also going to charge you something like 3-5% loan origination fee.