I’ve searched the forum a lot and did find that Ros do not support MLPPP as a client, but does it support it as a server?
Helo,
ROS has implemented Multilink PPPoE server features?
No. I asked the support in February 2015 and got this reply:
For now RouterOS does not allow to create MLPPP server.
We can not promise that this option will be implemented in nearest future, but we
are definitely planning to implement it. Most likely, it could happen within
version 7 of RouterOS.
So perhaps or not this feature will be implemtented in ROS 7 or ROS 8 or at some time in the next 20 years 
Good, so it will be implemented when I note need this feature