go to ffprofile.com
the only things you should not enable are resist.fingerprinting, and the 2 fields related to indexeDC and local DOMstorage.
install all extentions except umatrix, and then follow their guide to go to about:support. close firefox. delete everything in there, paste the exracted contets of profile.zip into that folder, launch firefox, install bitwarden.
if you really are paranoid youd be using qubesos essentially unmodifed os installs to appear as basic as possible.