Wifi roaming is pretty poor because it's entirely a client side decision (unless you have the AP forcibly disassociate a client - this is rarely done as it inte

Wifi roaming is pretty poor because it's entirely a client side decision (unless you have the AP forcibly disassociate a client - this is rarely done as it interrupts streaming / VoIP etc). APs can provide the client with a list of neighboring APs and things like 802.11r speed up the reassociation process when there's a complex backend authentication process like 802.1x, but it's still entirely up to the client when to roam. Ubiquiti's early products did provide a "zero roaming" option which faked one big network, but this was very inefficient bandwidth-wise as it required all APs to share a single channel. Proper network design such as minimizing TX power to encourage a client to roam due to a "weak" signal and maximizing coverage with lots of APs typically is the best way to get clients to roam reliably.