You can't do a HELOC on an investment property, For that reason, if you're house hacking, it's always better to get the HELOC before you move out of the property.One suggestion for future financing, look into Bank on Yourself policies.

Though I suppose many people would rather have new construction townhouses or a 3 or 4 story apartment project on the site.   

I would be looking at about 50 K loan and can go  upto 12 % interestTo be clear this is only for future ..most probably next year when I start to scale 

Either a) They are a “partner” to some extent or b) They will still want 20-30% down.To me, option B is a waste of time and money because I’ll still have to refinance to get my money out to do another deal.Option A would be fine if you can find someone to just put up money, collect their payments, and let you continue rolling it into future deals.

They'll put all their energy in the project, and you're buying time.

That would be a good way of creating future opportunity and strength over a HELOC.It really depends how much equity you have and how much you want to use.

I have found a number of infill lots for developers for large infill projects in San Francisco. 

If you have time to complete projects in your home, practice those skills and keep a log of how much time and cost everything was.  

Would rather not have to spend so much time myself on the next project.

I started a few more projects in 2020/2021 and then my wife gave me a small business to market.