Due to optimizations in the backend, since July 2024 HamAlert has been fully processing all spots from PSK Reporter again (before that, only a selection could be processed). See also FT8/FT4 spots & backend scalability.
Filtering spots based on spotter location (so you actually have a chance of hearing the spotted station at your QTH), band (so you don’t get spots on bands that you can’t work) and perhaps mode is always a good idea. If your conditions are overly broad, your trigger(s) will match thousands of spots per day, but due to the rate limiting, you will only get alerts for a random selection of them. Therefore, it is better to have the conditions as specific as possible so you will only get alerts for spots with a high chance that you can actually work the stations.
If nothing else helps and you’re OK with this random selection, then you can split up your triggers to include fewer special callsigns per trigger.