If it's not healthy, then it's probably not a good rental in the first place and you should probably sell it and get something that's a better rental (if you can't improve the numbers). 

I simply budget 5% of incoming rent for maintenance and 5% for future capital improvements and manage the properties as time goes and as things come up.For example, when a tenant moves out, I will look at the property and determine if any rehab/upgrades make sense at that point.

I would match those and stay clear of over improving the place. 

This project showcased our ability to add significant value through strategic improvements, resulting in a profitable sale for our partnership.

This will improve your odds of successful flips.When a wholesaler has a bunch of flip buyers coming to the house at the same time or throughout different times, your odds of getting that deal at a number that makes sense diminish.

Finally, don’t forget to ask for feedback regularly to see how you’re doing and where you can improve.

Techvestor's project managers direct local contractors to make the STR-specific improvements they desire.

They would have immediate control and responsibility for improvements and maintenance. 

What am I missing if I purchase, improve and refinance using commercial lending?

As for the rest of point 4 I think, in a vacuum, this might be correct but as technologies improve, especially LLM/AI products I think Agents will become even less important.