I don’t know how to start with this. Basically, on Wednesday the 11th of JAN, I stumpled across 2 softwares that may works with Qubes. One of them is DynFi Firewall via VGA ISO file, and the other one is ClonOS. I’ve forgot to download and try them in my Qubes, but basically, DynFi FW is a centralized FW that is open sourced and blocks any insecure things, such as ads and malwares, as noted on the site. On the other hand, ClonOS is the BSD version of Qubes with a lot more features. This OS, ClonOS, originally for CBSD, but it works similarly. Thus, ClonOS may/not works with Qubes.
Another thing is DynFi FW, this software IDK it works well with Qubes, but it can block malicious packages, such as ads and malwares, out of your sight/sites. It can be a load balancer if you are self-hosting your sites, which is self-hostable BTW. It can also hosted on virtual managers, such as Xen, VMWare, etc. As a result, DynFi is self-hostable and can be virtualize via Qubes-Xen.
Sources to reference: