Congratulations - you've just eliminated the vast majority of properties you choose to evaluate.

In my house I have a Maax which has the tub and lower part of the surround as one piece and then a second piece of the surround is added higher up-so it eliminates that join where the edge of the tub meets the surround where water tends to pool. 

Being specific helps eliminate confusion and keeps you on track.

This would eliminate the % fee and the concern of low-quality vendors.

The reality is that a property properly renovated to a high level and eliminating deferred maintenance that is also managed at a very professional level, can and will outperform a marginally renovated property with marginally good management.

What are your plans to reduce/eliminate these variance on the next build?

Why don't you use a bit different model where your potential clients can pay perhaps $250 (or a bit more if reasonable but no more than $500) for an hour meeting to talk to a real CPA who has been trained by you and determine whether or not they can save me money on taxes such as capital gains or ordinary income or passive income by forming structures that makes sense for using up various deductions and write-offs to the fullest extent to off-set the various sources of income and let them show me how they can eliminate my taxes down to minimal to zero in that quick session, it is like a preview session to what is possible given my actual data. 

There is a 10 year waiting list to get a voucher, so in my experience the tenant isn't likely to muck it up with unauthorized pets, guests, etcYou can eliminate 3x rent since the applicant will have a voucher.  

The card reader will keep track of the coins deposited so you know if the coin boxes are filling up.Some brands link everything together and eliminate the coins altogether but it may be all or nothing if it fails.How many machines do you have? 

This combined with the use of pet screening.com s and the non-refundable application fee has eliminated new tenant with bogus ESAs from applying  good luck