with mcsadmin the primary can be chossed with

Choose Primary

This function is lost and no equivalent in cmapi/maxscale exists.

In the maxscale module csmon is a function
primary

"The primary parameter controls which server is chosen as the master server. "

csmon is deprecated and only for 1.2 and below.

So we need a feature, where a user can define a primary
and maxscale keep this primary as primary back after columnstore choosed a different node as primary after a failover from columnstore side.