Even with my former partner (who was our 'PM / GC' on site for our projects), it was sometimes tough navigating the process, managing budgets and costs, and keeping everyone in line, including him. 

I feel like that sounds simple but in reality would hold up the leasing process for tenants that are not proactive. 

Due to item 1, adding an ADU can require years to start achieving any return (once the accumulated cash flow recovers the initial negative position).4) Adding an ADU is a slow process.

Since this is a rehab, you shouldn't have to worry about offering a builders warranty but here's some things I've become accustomed to doing to make the warranty, sale process and transaction process easier.  

That is not everyone's thought process but it is mine. 

That's the same chart/data I posted above.

Instead of having to enter personal info and upload an image of your driver's license for each Reporting Company, the Individual FinCEN ID allows you to input your personal data once and then link the Individual ID to your various Reporting Companies. 

How much will depend on how well their processes are designed.

Having a GC that will provide good documentation, itemized receipts, etc. will make the process much easier I've noticed. 

Even something as simple as utilizing ChatGPT to speed up certain processes such as asking for generalized information on a market's demographics and immigration patterns can be useful and save a lot of time.