I think using importmaps might be why it is restricted (see https://github.com/basecamp/once-campfire/blob/main/app/controllers/concerns/allow_browser.rb https:

I think using importmaps might be why it is restricted (see https://github.com/basecamp/once-campfire/blob/main/app/controllers/concerns/allow_browser.rb https://github.com/basecamp/once-campfire/blob/main/app/cont...) to some browser versions. One can try to migrate it to vitejs for example or any other JS/CSS build tool and it might have good chances maybe to work on older browsers.