@Frink
I assume you installed those extensions using Bazaar and not ssh right?
Barring you don't have ssh at all (With or without composer) you could try the following:
Delete the .js, .css files and the rev-manifest.json files in the assets folder.
Additionally, clear the content of storage/cache directory. (not the .htaccess file though).
(Almost what php flarum cache:clear does, though cache:clear is safer as it selectively delete things I think).
And of course clear cloudflare and browsercache as @clarkwinkelmann mentioned.
