You might check out Upwork to see if you can hire a programmer to write  a little browser plugin for you to do that.

I'm also a full-time programmer at Valor Credit Union.I am currently saving up and hope to begin my journey summer of next year with my brother-in-law.

its kinda plug and play and i have had several HVAC guys quote me on this. it would cost more up front but it would be a new system with warranty and i can add one thermostat that only i can control.  

If he built the program himself, he's more than confident/knowledgable to show you how to uninstall the software and even if he isn't a programmer, he would know how to uninstall his own software. 

I have wifi thermostats.

Maybe a programmer who developed their own product for them selves.  

hay Denita    if the barker in the panel dose not work or issues are not fixed after installing a new braker     some times the water heater too,  has a thermostat that has a braker that will pop (not being phased in right  or wired right. 

Luckily I have been married to a woman that has been saving for about 25 years as a computer programmer that is very smart.

I'm a freelance copywriter and I'm a programmer, I'm actually working on developing my own SaaS (un-real estate related) now.

Why not just install a $100 WiFi thermostat and require electronic access from your tenants to only monitor for such purposes?