We do digital leases. 

Then on the other side it handles the entire processes of agreement generation, digital signatures, etc. 

Selecting any calculator or program to compute APR, set it to display 8 digits so that it is not rounding and carry the computations out 3 decimal places to be in compliance with APR disclosures.

I'm looking to automate my digital rent collection and would love your recommendations on software that you have experience with.

While it is difficult and time-consuming to get approved, the main issue is that the interest rate will run well into double digits and, to add insult to injury, you get taxed on the interest you're paying and you're forced to take a life insurance.

One of my favorite features is the check-writing; it has a built-in mailing module that allows me to send digitally signed, physical checks to vendors (such as the city hall) that do not accept ACH.

Definitely can help to make the process as painless as possible and more efficient for both parties (landlord + tenant), and also offers digital leases. 

In reading many of the stories here I’ve seen people having quickly scaled to double digit doors with less capital up front, so my question is what is the best way to approach this if that is my goal?

That is my sweet spot for pricing.So here is what I have as my settings:Last Minute Prices = 30% discount within 35 days (Gradual)Orphan Day Prices = Weekday: 35% Weekend: None Discount for gaps between 1 and 5 nights applied within 0 and 8 nightsMin Stay Update Default :Fixed Weekday: 2 nights Weekend: 2 nightsLast Minute :Weekday: 1 night Weekend: 2 nights within 17 nightsFar Out :Weekday: 2 nights Weekend: 3 nights beyond 90 nightsWeekday: 3 nights Weekend: 4 nights beyond 180 nightsMin Far Out Price 40% premium of base price on weekdays and 55% premium of base price on weekends outside of 120 daysOccupancy Profile = DefaultRounding Last digit by 4 or 9If I could get the pricing to actually go up to my full base price within 3 days, that would be ideal...  

This implies there were tenants that experienced 4 digit per month rent increases.