According to anonymousplanet, Brave is arguably better at fingerprinting resistance than Tor Browser, so recommended choice as disp-VM of default browser.
So I think, Brave order to use making account on only disp-VM over VPN, keep of user anonymously.
Using sign up to VPN or Mail accounts, user must be make on whonix!
disp-VM(Using Brave) > sys-VPN(VPN account makes on Whonix) > sys-firewall > sys-net > access to sign up page(Using mail account makes on Whonix)
Reason of need VPN, many services are blocking from tor access.
If service don’t block to tor, unnecessary VPN, user had better to use only Brave tor tab.
Firstly user clones debian-12-template, and install Brave in this template(It call Brave-template here).
Installing in Brave-template is Brave only, if user needs to other app, they install and run other template.
Because block template-VM fingerprint.
If user fiest language is Hindi, user is setting Hindi as system language of template-VM, this is abused template-VM fingerprint.
So if user hope keep anonymously, must use vanilla template.
Secondly AppVM make from Brave-template.
This AppVM become to exclusive for Brave.
Next user runs Brave on AppVM, and settings change.
Danger of security and privacy settings disable all, hardening Brave.
Ending Harden, Brave makes many unnecessary files, they are most likely to commit browser and AppVM fingerprint.
Because user deletes all unnecessary files, AppVM change to disp-VM(It call disp-Brave here).
Process of unnecessary files deleting guide is this topic:
Pros of disp-Brave are not only block browser and AppVM fingerprint.
Brave has previous of change default settings without user permission, but disp-Brave can block from this threat.
Brave on disp-Brave is block from template-VM, AppVM, browser fingerprints, block threat from Brave.
And this is not need to security and privacy settings every time, user runs clean Brave one click.
Time of creating account only, Brave on disp-Brave with tor or VPN is safely Tor Browser on Whonix.
User must not use Brave other time, for sure!
Ending account create, if user hope keep anonymously, user must not use Brave for log in.
If this service is blocking tor access, user should be use Mullvad Browser over VPN.