Chrome extensions, chrome extensions, chrome extensions. I cannot stress this enough. This is the "hidden application pool" that students, teachers, and principals pull from. There is a cottage industry that does nothing but figure out extensions to create, disguise them as "informational sites/extensions" in order to give kids access to games so that they can show ads. It is a constant thorn in the side of IT.
If you have a chrome extension ...teachers will find you.
Most ERate customers make purchases on 5 year contracts or a "buy once keep forever" model...month to month is a pariah. This is due to the fact that with ERate government funds projects, software, and infrastructure can be purchased. ERate funding is viewed like the lottery.
In Georgia at least there is a state run "Tech" board (email list) where different techs exchange ideas. They make recommendations to the individual school boards. You get someone to champion you there and you will pick up several districts.
...again good luck.
More specifics... https://www.fcc.gov/general/e-rate-schools-libraries-usf-pro...
ERate has a 5 year cycle for rural school districts. The problem you are solving is a very real one. Also I would look to people like LightSpeed (produce Rocket appliances) for bundling. Possibly see if you can provide a "service" on Clover as well. Good luck.
I took a look at your site. I would also recommend a chrome extension with easy management in G Suite. 10k customers is one rural school district for you. Many, many of them don't do Apple but use G Suite, since it's free, along with Chromebooks.