We would like to offer full support of 'link_mode: active' and although it should work we want to make sure it has gone through some testing from the QE side of things.

From corosync man page:

link_mode

This specifies the Kronosnet mode, which may be passive, active, or rr (round-robin). passive: the active link with the highest priority (highest number) will be used. If one or more links share the same priority the one with the lowest link ID will be used. active: All active links will be used simultaneously to send traffic. link priority is ignored. rr: Round-Robin policy. Each packet will be sent to the next active link in order.
If only one interface directive is specified, passive is automatically chosen.

The maximum number of interface directives that is allowed with Kronosnet is 8. For other transports it is 1.