Hello, unfortunately it is not that easy to determine which tab is active and what page is loaded and update the addon state accordingly.
For the support drop of FF56-59, as I wrote in a different response: The API we can use did change, to support future versions we had to change the methods used.
https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/proxy/register
https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/proxy/onRequest
FF56 was released in 2017, we can not go through the extra effort to support such old versions, if that is even possible.