Finally! I found someone who shares my worries about multi-stakeholder co-operatives. I think strengths of a co-op structure can be decreased, and the disadvantages increased when they have the problems of a co-operative with multi-stakeholder membership. Andrew Bibby is described at the International Co-operative Alliance (ICA.coop) . And at Bibby's own web site.
hypothetical FLOS services consortium
If a new consortium of diverse groups wanted to hire professional support for FLOS technologies together, they wouldn't need to be a multi-stakeholder group. They could have a single class of members if they were all consumers of their new shared-services co-operative. Services could be anything consumed by the membership: maybe user support, software configuration and development support, legal support of the FLOS licenses they depend on, or etc..