I would say the difference is largely a question of which is the better interest rate - the heloc vs the rental mortgage.  

If rates remain higher for longer or go up, then maybe best to wait. 

This, however, changes not only from county to county but also by neighborhood, zip code, school district, etc.Another change we are witnessing in real-time is increased seller’s concessions, which can go towards financing closing costs or buying down the interest rate.

Your interest rates are often higher for a non-owner occupied home  than for a personally owned home as well.   

I am not willing to put my credit rating in the hands of a tenant. 

My current primary ( scenario 1) Keep the primary for the life of the loan ( current rate is 4.5 so i dont see my self refinancing anytime soon)current home value 1,150,000Loan amount 935,000appreciation estimate 5% per year after a 28 year hold and the house is paid off I would have a house worth 4,312,000$my current mortgage is 6125$ ( piti) included My second option( scenario 2) Sell the house, walk away with $150 ,000 ish in hand and put that into a low cost index fund Rent a house elsewhere for about 3000$ ish and take the extra 3000$ im saving everymonths from not having to pay my mortgage and puting that money in the index fund as well I ran the numbers on both of these scenarios and doing what I mentioned above would break even at about 28 years meaning my stock account would be worth 4.3 million just like my house would , but the only is that holding a house for 28 year would mean 28 years of property taxes, loan interest ,home insurance and repairs etc whick I calculated to be about 1,200,000$ at minimum which raised my eyebrows to say the least Also i understand that each of these options ( stock market vs real estate ) will have there tax consequences ( long term capital gains) so any thoughts on that would be appreciated as well.  

What interest rate is the seller offering? 

Honestly, long term investor loans and DSCR loan rates aren't really any better than that right now.

If he chooses to stay, review his finances to verify he can afford the new rate, then lock him in with a new lease.If he can't/won't accept the rent increase, give him 60 days to find a new place.

Expenses are relatively low, occupancy rates are as near to 100% as you can realistically get.