We had our first Jamulus band practice this week, it took a few attempts of setting things up given that we are all remote and have totally different home kit, we were sans our drummer this time round and hope to all be together next week but a very promising first session. We are all in the UK and all were hardwired to our routers, latency was around 40ms end to end so yes it was noticeable but we managed, we had fun and played through some of our slower tempo covers.
You do need a USB Audio Interface with ASIO (pc) or Core Audio (mac) , if using a Helix family device you need to install HX Edit and that installs the correct drivers, I disabled local monitoring by sending my patch output to USB 5/6 so the Jamulus client takes input from USB 5/6 and outputs to USB 1/2 so I can still leave my headphones plugged into the Helix LT
There are a couple of very helpful Facebook groups and the Sourceforge discussion group is very active and helpful , my advice is to focus on your home setup and use a public server that has low latency to get going, then if you want to you can explore building your own
http://llcon.sourceforge.net/
Happy Jamming