The website you mentioned show Metamask, which support 4 different Browser. Why don't you just use Firefox and download Metamask?
Due to privacy converns i won't use Metamask.
This+TOR will hopefully be enough to protect my privacy/security while the wallet still works as expected.
Since you apparently takes security/privacy seriously, you might want to check what kind of files accessed by the InfinityWallet (you could use
lsof or
fuser) and use Firejail/Apparmor to restrict it.