Smart-Target VS foundry-user-latency

Smart-Target - allows customization and ease of use for Foundry's targeting system.

Not PF2e-specific, I'd also recommend Smart Target, which lets players target tokens with either Alt+Click, or simply a click (configurable).

Smart Target v0.9.7 Bugs URL

Smart-Target

In addition to Easy Target, which others have recommended, if you're on 0.8.X there's Smart Target which makes it so that clicking on a token you don't own targets / un-targets it. Easier than the "double right click" rigamarole.

User Latency v1.3.8 Bugs URL

I own the library Ping Logger which just adds in the latency of all the current users next to their name. I find it incredibly helpful and useful, especially when people get hiccups. If you see someone spike to 2000 or something, you can expect to just wait for them to come back.

You can check if the lag is network related with https://foundryvtt.com/packages/ping-logger

We had a similar thing occur in our Starfinder game, though the symptoms were more widespread and affected everyone. The slowdown affected everyone: simply moving across the canvas took ages, and actions took very long to show up in the chat log. This would also show up in the Ping Logger output as a very high ping (12k ping, which is 12 seconds, the time it took any one of our computers to querry the host's computer).

I would advise trying self-hosting first and if it works well for you then you're good to go. If you have lag, then perhaps look into a hosting platform. I'd also advise getting the Ping Logger mod. It shows the ping speed for each user next to their name. That way you can see if any lag is user specific or if all users are having issues.