No matter how I try to select the boxes, it doesn't recognize them.

It may work fine for certain applications, but not in my situation (Firefox v84.0.2 with Salesforce). Too bad, cause I need to turn off sh*tloads of checkboxes sometimes. These checkboxes are simply sitting inside an html-table, nothing fancy or unusual. Still looking for a working alternative.

Not working currently.

This does not work at all for me in Quickbooks Online.

Work great until it didn't. Suddenly stopped working at all. i tried reinstalling. I wish you better luck. Says it requires Firefox v.57. Not up to date since I'm running v.59.