ROS at this time only supports 1 connection mark that lasts the life of the session. This prevents the writing of efficient mangle code to handle a combination of QoS marking and multiple simultaneous WAN ingress/egress pathways. Support of this currently requires creation of an N x M size connection mark matrix with corresponding duplication of rules. Implementation of a connection-routing-mark in parallel with the current connection-mark, both lasting the duration of the session, would provide this functionality with minimal configuration overhead.
The article I wrote showing QoS setup for RingCentral services has many connection-marks and mangle chains. Properly supporting multiple active WAN links with correct routing would become a nightmare of code/configuration duplication...
Tim McKee
WN9Z