After tough and hard CTRL+F search quest I found this:
"multicast-enhance (enabled | disabled)
With the multicast-enhance feature enabled, an AP will convert every multicast-addressed IP or IPv6 packet into multiple unicast-addressed frames for each connected station.
This may improve link throughput and reliability since, unlike multicast frames, unicasts are acknowledged by stations and transmitted using a higher data rate.
Default: disabled"
https://help.mikrotik.com/docs/display/ ... 20disabled