ROS Level 4 License limits the hotspot active user to 200.
My organisation can have up to 300 active users, however at any time only less than 100 has active rx/tx traffic.
What is mikrotik’s algorithm if you exceed the active user limit for the license level. Who gets dropped first.
I have never tried but from logical side i would say no users can be logged in if there are already 200 active users in /ip hotspot active
That means you could help yourself with a script which checks on a regularly basis if there are more than (just an example) 175 users connected. If its true you could disconnect everyone who has no active tx/rx traffic thus having more space for other users.
When it reaches the user limit, I can think of 3 possibilities:
(1) prevent new logins, or
(2) drop the oldest logged in, or
(3) drop the oldest and inactive logged in (unlikely but I would be pleasantly surprised if it behaves this way)
Im really sure (1) will happen - but as i said i never tried this 
But option (2) and (3) would use a different logic behind this check. Its more easy for the Router to check whether there are already 200 connections and just dont accept the next one until that number is < 200.