There is a hard 10 client limit for pixelblaze AP mode WiFi. You wouldn’t want more than 9 clients/followers in that setup because your phone/laptop wouldn’t have a spot.
There is a roughly 10 follower recommended limit. 10 followers works well for all supported features.
You can have more than 10 followers when you use a dedicated WiFi router.
Some issues may happen if you connect a lot more than 10. Usually problems arise when you power up everything at the same time, or are sharing sensor board data with lots of followers. I found issues with 30 followers and no sensor board data, where sometimes it would take a long time for things to sync up but it wasn’t completely broken.