Hello,
Based on this diagram from the Mikrotik Wiki:

what would be results if ‘max-limit’ is changed to 6mbps and there are 2 Users, one with a CPE radio interface of 13.5mbps and the other with a radio interface of 2mbps.
This is our actual situation with 900 mhz equipment used in a small WISP.
Ideally the faster interface would download at 4mbps and the other at 2mbps but I doubt this algorithm will produce such results.
Thanks.