Yes you can. When logged into RUMvision:
go to your domain settings;
click on "configure snippet";
go to the "Advanced" panel;
Scroll to "Privacy and consent";
uncheck "sessionStorage".
Do note that with sessionStorage enabled, our library becomes more performant as less checks have to be done during page navigations.
Data (especially unique versus total pagehits and returning visitor-rate) becomes more reliable too with sessionStorage enabled. But in general, our monitoring script will work perfectly fine when disabled.