Throw another property in the mix and now my HELOC balance might be $70k, with two different properties both paying varying monthly amounts towards their respective balances, that ultimately lump into one larger P&I monthly payment.I tried to get the bank that my 1st mortgage is through to allow me to have multiple lines of credit against it so I could have a HELOC for each property and keep it straight that way, but it was against their policy to do so. 

Great, that means Person C could have picked up 4 houses for $100k a pop (25% down each) before the inflation, each now worth $120k... into it for $100k like everyone else, net worth value $180k.Buying stocks has significantly lower closing costs than houses, so Person B would actually beat Person A, but C would still come out ahead.

Throw another property in the mix and now my HELOC balance might be $70k, with two different properties both paying varying monthly amounts towards their respective balances, that ultimately lump into one larger P&I monthly payment.I tried to get the bank that my 1st mortgage is through to allow me to have multiple lines of credit against it so I could have a HELOC for each property and keep it straight that way, but it was against their policy to do so.

I'll try to be brief and straight to the point.

You still come out ahead in the end.

IE consulting, stock grants (RSU’s), straight W2 income?

At least with a printed letter, they can just throw it in the trash if they're not interested.Please let me/us know what you decide to do, and how it turns out.You have a bright future ahead of you, best to you!

I know the seller personally so these are straight from him. 

I'm preparing an offer on a SFR in the Seattle area (Eastside) ahead of the offer review date.

Thanks ahead of time for any responses/help given.