Curious if anyone knows of a software/hardware product to create a 3d virtual walkthru similar to what is seen in this video (7:27 mark)? 

I asked that because I needed him to confirm he would move out before I accept the application fees from the potential tenants.And after the potential's background check, I found they are undocumented immigrants, I cannot let them move-in.

I'm currently working on a new property management platform that combines software with a trained team and AI.

I work for MRI Software.

If you talking commercial only then self storage would be at the top of my list if application then office space..

local boards can and do switch MLS software providers but to your point, whatever one the local board chooses you’re pretty well stuck with. 

Are there any popular and free design software out there??

I wish the Attorney General had some software in place to handle this, since there are software packages out there that can review the “education grade level” of text - so it could really be automated that way, and then each time a change needs to be implemented the new document(s) can be submitted; I imagine an electronic receipt of some sort would be issued to confirm approval should the AG ever implement such a thing, along with keeping a copy of the document(s) in some database as a “just in case” they are needed.

I'm working on getting a third STR but struggling to find a lender that will use STR income towards the mortgage application, therefore making my debt to income ratio too high.

I'd ask the seller/seller's agent for proof of payment and a copy of the leases (if applicable).