Hotspot and User Manager License RBXX doubt

Hi, I’m planning to implement a Hotspot with User manager UM, with a RB750 (Lv4 Lic) or RB450(Lv5 lic) for more than 80 users, but I dont understand exactly the license limits for UM here http://wiki.mikrotik.com/wiki/Manual:License:

If would be the case that UM for RB750 and RB450 does not allow to manage more that 50 users. What would be the suggested solution?