Doing some testing, and in the queue documentation it shows that max-limit=0/0 should be unlimited and and example is given to use it to omit a system from rate-limiting:
From https://wiki.mikrotik.com/wiki/Manual:Queue
Probably, you want to exclude the server from being limited, if so, add a queue for it without any limitation (max-limit=0/0 which means no limitation). Move this rule to the beginning of the list, because items in /queue simple are executed in order one by one if router finds rule that satisfy certain packet next rules aren’t compared:
First, why do we have a priority= setting when the rules are processed in order. What’s the point of that?
Second, max-limit=0/0 is not unlimited in my system. Consider the following:
0 name="fast" target=192.168.11.12/32 parent=none packet-marks="" priority=8/8 queue=default-small/default-small limit-at=0/0 max-limit=0/0 burst-limit=0/0
burst-threshold=0/0 burst-time=0s/0s bucket-size=0.1/0.1
1 name="slow" target=192.168.11.12/32 parent=none packet-marks="" priority=8/8 queue=default-small/default-small limit-at=0/0 max-limit=100k/100k burst-limit=0/0
burst-threshold=0/0 burst-time=0s/0s bucket-size=0.1/0.1
This setting results in 192.168.11.12 getting 100k/100k. However if I assign a very high amount of bandwidth to 0, then it works correctly:
0 name="fast" target=192.168.11.12/32 parent=none packet-marks="" priority=8/8 queue=default-small/default-small limit-at=0/0 max-limit=1G/1G burst-limit=0/0
burst-threshold=0/0 burst-time=0s/0s bucket-size=0.1/0.1
1 name="slow" target=192.168.11.12/32 parent=none packet-marks="" priority=8/8 queue=default-small/default-small limit-at=0/0 max-limit=100k/100k burst-limit=0/0
burst-threshold=0/0 burst-time=0s/0s bucket-size=0.1/0.1
So, it appears that either the documentation is wrong and max-limit=0/0 isn’t unlimited, or there is a bug in 6.47.8 (RB4011).