Then you could buy now before competition becomes crazy again and refinance when rates come down.

I'd rather go with a conventional loan to get a lower rate and fee.

Rent out your units at, or slightly below, the market rate and gradually increase rents YOY (2-2.5%).This strategy will allow you to get your foot in the door with a low down payment AND less competition.

Regarding "One major downside is most HELOCs are adjustable rate, and I'm certain rates will be increasing even more in the near future, so finding a bank that has a rate-lock option is my hedge."

The key is finding the areas / neighborhoods with strong rental rates that are not saturated with too many LTRs.

Between rates being higher and terms being shorter Helocs can also have issues when it comes to DTI and not having reserves. 

In this high-interest rate/high-price market, house-hacking is more about offsetting as much cost as you can.

I am currently renting at 40% below market rate rent and will be putting 5% down.

You can get higher but the rates will be higher as well and it will be a lender that doesn't sell the loan to Fannie. 

Especially with higher interest rates and also location dependent might be more geared toword appreciation.