When I hear participation model I do not think of concrete structures either, but rather, approaches to structuring (civic) engagement (in non-electoral contexts). My home town uses a commissions model to structure civic engagement there. Occasionally, it also draws on other models, for instance, it will hold consultations, or even one-off workshops or meetings that are open to the public but designed to appeal to specific stakeholder groups and it will try to tailor the formats and methods used at those meetings and workshops to suit those groups.
Partizipierende in Beteiligungsformaten haben ein gutes Gespür dafür, ob sie lediglich als konfirmatorisches Organ einer bereits vorab politisch bestimmten Lösung fungieren oder ernsthaft Einfluss auf das Lösungslayout nehmen können
I think "konfirmatiorisches Organ" implies that in this sentence that "Beteiligungsformaten" are actually "participative bodies". If there is some reason (in the wider context, for instance) to think that other kinds of participative processes may also be meant, then I'd add them: for instance "participative bodies/forums" or "participative bodies/processes"
Edit: format could be used to describe a workshop or meeting too, rather than specific formats used there, but if you are talking about something in which real people involved, you will probably no longer be talking in terms of formats or models, but rather in terms of bodies, processes etc in which those formats/models are realised. I've noticed a couple of times that the German usage (in the field of civic/stakeholder engagement) is different in this respect.