Major hotels will upgrade their rooms, bars, restaurants and casinos frequently, sometimes every 3-4 years.

I do this frequently, it's a great tool for my out of state buyers - BUT only with buyers that have a signed buyers brokerage agreement and I've talked to their loan officer (or seen a bank statement). 

But more frequently those who appear to scale portfolios quickly are either lying as Chris correctly stated or are highly leveraged and/or are fee developers who own minimal ownership interest and are backed by LP equity.You also shared your objective of holding your assets for a long period time.

Annual lump sum payments offer more impact and flexibility but less frequent progress and potential temptation to spend.

They are also not allowed to advertise offerings, so I would at people sharing knowledge pieces, frequenting the podcast circuit, and generally sharing knowledge.  

also for cars, don't trade them in frequently. 

And presented in very complicated way, hard to bring them to an apple to apple comparisson.One way to mitigate the lack of a net metering agreement is with a battery system (see Tesla Powerwall) - a very expensive way to become a truly self-sufficient energy producer (basically you become your own power plant), which rarely makes financial sense unless in a region with frequent power loss or in an off-grid scenario.

Since you are only doing face time viewings I am not sure of the cadence you are doing these but I would bump that up to be as frequent as possible if going physically is not feasible.

With reduced turnover rates, you can avoid frequent vacancies and the associated costs of advertising, cleaning, and preparing the property for new tenants.

Doing an OOS renovation is even more challenging - you can't physically check on the property unless you fly out there frequently.