My assumption is that the pandemic fueled vacation rental boom, both in terms of users and owners is going through a bit of a rebalancing.

You cut a check, and wait for the return. 

The toughest part about the renovation is going to be cutting out 500-ish LF of concrete to install underground plumbing in the new units.

But this is not where you cut corners, particularly if you are in a state where the landlord-tenant laws favor the tenant. 

In other words, why not just do it myself and cut out the middleman - which is you -?

I would second Suzanne's reply and add that if your property manager is being really stubborn about it maybe you can work something out with them and they get to take a cut like they normally do out of the gross rent (something like 8-10%).

I have not decided when my time will end, so 65 may be middle-aged for me.Don't cut yourself short.

Buildium sells renters insurance directly to our residents but sadly we do not get a cut.

But I don't what to waste my time showing the property and sifting through applications that I know won't cut it.Thanks in advance BP community!

I think it's also important to think about where your tax rate is going (likely up given your increase in income and individual tax cuts set to expire in 2025).