Based on the research I've done regarding short term rentals, it seems like most owners recommend using a pricing tool to effectively reduce vacanies.This makes sense considering the high price fluctuations STR usually have.

My market, San Antonio, tends to fluctuate between A- and A+ over time (I've been tracking for 3-4 years), so I'm not sure how useful the current grade is at any give time.

I’m a busy real estate broker where my day to day schedule can fluctuate greatly.

The distance of the ADU to the utility connections and what is in between (hardscape or softscape) will also fluctuate the costs.

Again, with an ad valorem system, their tax rate should fluctuate yearly to meet a balanced budget. 

Appreciation can fluctuate up and down.  

Rental properties come with management responsibilities, market fluctuations, and potential vacancies.

In addition the safety risk in mexico fluctuates dramatically.  

Appreciation is largely caused by factors outside of your control, such as the path of progress, changes in local demographics, micro- and macro-economic fluctuations, etc. 

This will fluctuate and these estimates are conservative IMO