I understand that you are seeking input w.r.t. participation of other member-organisations in the Open Chain Project.
For ca. 8 years I have been a member of the Board of Directors, Secretary and Treasurer of a membership-based non-profit standards organisation (NFC Forum) and I would like to share the thoughts and experiences we had w.r.t other non-profit organisations being a member in the NFC Forum. During the time when I was active in the NFC Forum, Andy Updegrove was the legal counsel who guided us with his team in all of these matters.
The initial thoughts about non-profit membership were to allow other organisations to get involved (at low cost) in the early phases of the standardisation process. However, that was more on the track of 'reading' drafts and not with active contributions. The reason was that active contributions required an IPR statement to guarantee FRAND conditions on all IPR licenses (essential claims, standard-essential patents), and this was impossible to get from the members of a non-profit member.
Non-profit organisations as members in the NFC Forum would only be allowed in a non-voting member role, as there were concerns about anti-trust compliance and improper aggregation of voting power. Over time, apart from other non-profit organisations, also academia liked this membership class for participating in the NFC Forum.
For real peer review of standards and a 3rd party commenting process, the NFC Forum established 'Liaisons' with other organisations, which would then receive a close-to-final version of the drafts of new specifications for review and comments. It has shown that a formal liaison, which has received approval from the board of directors of both sides, was a much more serious thing and delivered more structured inputs to the respective other side.
I am well aware that the structure of The Linux Foundation and the Open Chain Project is very different from the structure of the NFC Forum. The net takeaway, however, might be that the real contributions in the organisation should come from direct participation (and not indirect through members of members), and that inputs from other organisations (and that can be in both directions) best come from formal liaisons with other organisations, where the inputs (responses on RFCs) are approved by the technical committee (or another high-ranking technical body) in the other organisation.
I am happy to further discuss this with you or answer any specific question you might have.