Chapel Hill, NC student housing seems to be doing well, and I'd say it's is experiencing a similar demand as pre-pandemic if not more so since there are more students (including first years) looking to get off campus housing to get as close to the traditional "college experience" as they can during these times.

Appreciation is a side effect of supply and demand. A

And then with you HELOC, you can tap that remaining equity on demand as purchase money/rehab funds/or lend it out as hard money/transactional funding to other investors.

So if getting sellers to cooperate is tough maybe you should demand a long closing to accommodate finding the replacement. 

I understand it's a mixed use so there won't be as much demand as if it were a true residential building.

If you live that close and only have one rental, it's not going to demand a lot of time.

If I'm going to have deal with all the additional regulations and headaches that have come out of COVID, I will demand a higher rate of return. 

They are in demand as well!

Lenders cannot request/demand a lump sum payment at the end of your forbearance term.

In your case, it may be helpful to use two different contracts, one for your initial offer without the DD, and if they want one, you can have a second contract that has it in and just keep it minimal.Most wholesalers will pay the DD because wholesale homes are very few and far between in Charlotte, there is no shortage of demand as everyone wants rehabs here.