I used to find this information on the County Recorder's website of whatever County the property is in.

I understand this does not answer your question but it is an important factor I thought I would share since im currently in a situation with an hoa auction purchase.Make sure you do a lot of Due diligence on it.Most county records are public information type in the parcel number most liens should appear. contact a title rep and see if they can dig a little into it.

How do I go about updating the new square footage in the records, at least by the time I sell or advertise as rental in the future?

It was at the time my personal record year, and with rates up obviously that can't have been based on refinances. 

Orlando was literally built for tourism and already has specifically zoned areas and great resort communities with proven track records without the fear or local authorities or an HOA to take it away.Happy to dive deeper into this with more specifics if needed, but hope this has some value!

All real estate transactions are public information in my state so the County Auditor website has property information as well as the recorded owners.

Like what @Tim Swierczek said, lenders may be hesitant to financing this structure without some of your capital involved, especially if this is one of your first deals and you don't have a proven track record. 

The easement needs to be pulled from the land records and reviewed.

Experience, track record, referrals. 

If you don't already have a Realtor I would suggest finding one in your area with a track record for helping clients find house hacks/investments and ask them to connect you with a few of their preferred lenders!