You could switch over to that instance and just use the local tab, then subscribe to whatever you had previously. Stuff from beehaw and other instances will still show in the All tab so you wouldn't be missing anything. That would allow any new communities on waveform to still show without manually following them. Apart from that I don't think there's a way without manually subbing to each one and going back to check for new ones every once and a while.

I'm definitely looking into automation and tools in Foundry to make things easier. Luckily there seems to be a good amount of community plugins available for both 5e and Pathfinder. I might do a 5e one-shot first to get some experience using the tool before I move to a new system. I also missed the humble bundle, but good to know it comes around a few times a year!

Our main group likes playing coop games. Some of our favs are Pandemic, Fuji Koro, Sanctum, Until Daylight, and Betrayal at House on the Hill (which we nicknamed spooky house).

Somewhat similar to you. I've mostly played 5e, and am playing in two active campaigns currently. However I purchased foundryVTT recently and am teaching myself Pathfinder 2e so that I can GM my first campaign down the road.

I really like the 3-action economy Pathfinder has, and the way bonuses and penalties work compared to the 5e system. Though there's so many choices in character creation it can feel a little overwhelming.