Do I wait another year to save more, or do I look into a HELOC or a VA cash-out refinance? 

In the long run it would save you $. 

You will learn a lot on your own home that will save you time and money on investment property.

I think the main thing I am learning here is to adjust the profit share between myself and my private money partners.

They get a higher return since they are covering housing cost, have the $250k per spouse primary residence deduction in gains, is a savings account, higher leverage position, lower interest rate possible, will pay more premium for location, etc.House might be overpriced for REITs but not for home owners.  

instead, saving that cash for a house hack is such a better use of it."

Now that I am in position, I would like to place a mobile home to generate some passive income, but I don't want to use my savings for the down payment.

Begin by targeting distressed properties in gentrifying neighborhoods, securing financing through hard money lenders or private investors, and focusing on cost-effective renovations.

I'd consider real estate debt funds and private lending but that's not on my immediate radar right now. 

If you have access to private equity then sure, but if you want to buy properties yourself then at best you are looking at 1-2 per year if you have really good income. 3.