You can also use the cash flow from your investment property to pay down your HELOC faster (use it as a checking account strategy).

I can get sale data in general much easier and faster than every trying to look on Zillow. 

Cash for keys seems a better (faster/cheaper) way to get them out if you're set on doing that

If you wait until later in the construction to start the move out process, you may end up stalled anyway, just at a later point when more money is tied up in the deal (and if you're using a bridge loan that can be a significant difference in holding costs if your interest is based on total drawn amount).If you get the tenants out early, you can likely move faster on the construction which may very well be comparable to doing things one unit at a time. 

Suggestion would be to focus on ROI and if that works attempt to secure good SF homes faster.

Make everything in your offer strong.....more money, more down, more earnest money, use the seller's choice of title company if they have one, faster closing times, no option period, tighter financing approval times.

I'm all about starting and getting your foot in the door, but make sure you understand the strategies that will make you succeed faster rather than just gettings pads under contract. 

Something else to consider is that a lot of property investors are institutional investors, so if there is a market crash and prices are "great" your investment dollars are now competing with tons of investors that have years of data and have cash on the sidelines waiting to be deployed, and can react much faster and clearer than a new investor just starting out. 

Also, this approach allows me to scale faster.

I believe you could do something faster than the 6 month seasoning if you did Delayed Financing at 70% (for 2-4 unit) purchase price or 100% HUD whichever is lower.