'Firefox for Parrot OS'
it's 128.x ESR shipped with latest Parrot OS, customized by Parrot OS devs (that is a Linux distro).
not running through Tor (out of convenience) while visiting F95 right now, because that had a bit of a negative impact on DL speed and takes several extra 'tweaks' to work around that. i'm somewhat lazy in winter.
Parodos right, Mega doesn't ask xss or anything else, so the browser wouldn't complain or deny (on tight settings). they do it all with cookies, i suppose. swisscows hadn't found any trackers on it, either.
i just don't know how much more effort that would take to set up and all that, given you already use mxdrop..
cxx on paranoia days i just use 'Parrot-on-a-stick' which is a Parrot secure image installed on some -r USB thingy, boot from that and execute solely within RAM. can't go more virtual than that, hehe.. but can't save a thing then. no drives but RAMdisk.