I had a similar reaction when I was first made aware of this late fee.

Given the surprising positive reaction, I'm expect a couple years of backlog.

Should I only raise specific unit sizes at one time to see the reaction?

Now your 1st reaction is- I don't have the money for a buy and hold so how can I do a flip.  

Post Covid reaction and low interest rates.

I don't think I would get the same reaction with vinyl.

In such a short time she could be ill or in an accident and the notices you already sent will probably get you a reaction.

Have you done any reading about the state supreme court's reactions to ordinances like this? 

a few reactions - -i don't think 'getting involved in real estate in other ways' is going to be a major factor that will accelerate you in any way. 

Now, we have many homeowners with the lowest interest rates in history, who are more reluctant to sell or move, as they would otherwise be, this in turn helps keep inventory low, possibly keeping a lower floor on prices or at least, making it more difficult to guestimate market reaction.