I was wondering if anyone knows a nationwide lender that is doing 80% LTV refinances on residential multi-families.

Hey Thomas, we can offer investment purpose loans for Residential & Commercial properties nationwide.

If so, does anyone know/recommend lenders that can service nationwide, or specifically in TX, FL or AZ?

It's more reliable than Stessa's due to QBO having a secure relationship with a ton of banks nationwide.

My company works nationwide, feel free to shoot me a DM.

Or, are you saying any local lender versus a nation-wide lender? 

The IRS is going to see that as you buying from yourself unless you own  50% or less of one of those LLCs.You can use any intermediary as long as they have a national footprint.  1031 is a federal statute so it's form is the same nationwide. 

Something to understand with 'development' is it is very regional, and therefor difficult to provide good meaningful advice that translates nationwide.

Does any know of a nationwide HML that will accept crypto statements  (such as BlockFi or Celsius) to show liquid reserves?

One thing to keep in mind is that different states can have vastly different regulations around lending and borrowing, so lenders may operate only in specific states vs. nationwide.