In case anyone’s interested I’ve done a bodge to get round this.
In the disposable template add this line:
cd <path_to_>mullvad-browser; ./start-mullvad-browser.desktop
At the end of the .bashrc file in the home directory.
Then when you launch the disposable’s terminal it automatically starts the Mullvad Browser.
So you can still update like normal in the disposable template.
It works fine except I get two instances of the browser not one with this error message:
bash: cd: Downloads/mullvad-browser: No such file or directory
Launching ‘./Browser/start-mullvad-browser --detach’…
[user@disp8364 mullvad-browser]$
Alternatively there is:
of course . . .