You've got some numbers to tweak here.

Yea start tweaking numbers based on the property features i.e., is it remodeled and has a new roof?

Appraised at $550k, but with some tweaks and rent raises, I’m estimating I can get the value up to $925k-ish within a year.

Just some tweaks to increase your deal funnel, decrease your timelines, and increase your velocity of money. 

Are your current work habits serving you well, or would you like to tweak them a bit?

@Todd Dexheimer made a good comment about convincing your investors why your strategy is solid, but I want to tweak and build on it.

It looks like the spreadsheet needs some tweaking. 

In the end since our credit was excellent I think we could have done just as well if we went direct to a local lender.Also 5 plus units changes fire code compliance in our area so we needed a fire alarm system approved by the town which the building had but there were some tweaks to be done.

In order to justify their list price they often have to tweak the numbers.   

I would not quit, but would advise to possibly tweak your verbiage (ask others what they write in their letters) and practice speaking to a motivated seller.