Just wanted to share what I think is a pretty cool, easy pairing of Qubes plus Zerotier that allows connectivity between other networked devices and specific Qubes.
For instance, I use KDEConnect on an AppVM with Zerotier installed to connect to KDEConnect on my Android Phone.
After installation of zerotier on an appVM, opening up Zerotier communications was as simple as changing the iptables on the appVM
allowing traffic on the zerotier interface
iptables -I INPUT -i zt3xxxxxx -j ACCEPT
iptables -I INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
I then was able to use KDEConnect and pair with my phone.
hope this helps others!