As I understand it, the lender should not count the entire PITI of the loan against the borrower in this case, but 25%. 

Is counting on appreciation the only strategy in a market like this, or are there points of view?

Does 469(h)(5) specifically mention ability count spouses material participation even if filing separately - didn’t see this ….

Some lenders also count your retirement account as reserves.Seems like you’re on the right track, keep looking in your buy box so you know what a great deal is when you’re ready to buy.Wish you the best.

My lender isn't counting my 4 fixed and flipped in 2013 and also my 7 years of apartment management from 2014 to 2021 towards my investor's experience.

I also more generally disagree with @Jason Wray's advice to cash out refinance, on two counts.  

Also, I haven't gotten a straight answer on this, but I think depending on the lender, the heloc payments may be counted in different ways towards your DTI.  

If you subsequently purchased a property for 200k, would you count gains/losses against the 50k you now put in or against the 25k you started with as that’s what you’re actually out of pocket, depending on how you look at it.I hope I worded that clearly 

What you should do is not count the good reviews, but look into the bad reviews.

Only you and your agent can make the decision.If you buy it,  count on finding unexpected problems that require fixing, and make sure you have the cash on hand to cover them.