With interest rates so high right now and property values up so much in recent years this would certainly help us when looking. 

If you're already at a good place with your portfolio, and just want to maintain rental income, hang on to the property with it's super low interest rate and positive cashflow.

There's a lot of research you could do on VRBO/AirBNB/AirDNA to compare similar properties in terms of rates and occupancy, but my experience is that Gulf Shores and Orange Beach are more popular because of the nearby amenities, nightlight, recreation, and other things to do. 

My mortgage interest rate is 3%.

We're looking at buying an STR to self-manage but with rates and prices where they are, the cash flow projections are dismal.

( I know there are certain rules to the 1031 and having 3 separate sales may be a little challenging) Also,  I thought about just refinancing the 3 properties, but the rates are a little high to cashflow well.  

Interest rate higher.

This can reduce occupancy and reduce the average nightly rate (as compared to a higher nightly rate and lower cleaning fee). 

However if you are charging your Short term rate maybe you do. 

interest rates have more than doubled since the end of 2021.