Roaming in WiFi network is a function of client, not AP (AP can assist, but that’s the client who always makes the roaming decision). Mikrotik in station mode (i.e. wireless client, not an access point) used to be a very poor roamer. I guess now the situation is going to be better.
It is not, I guess.
andreacoppini sent a couple of great posts on the topic of roaming in WiFi networks. Here’s the links: first, second.