Let’s clear up some terminology. First, there are “single panel” sails, these are made from a single, flat piece of “cloth” with curved edges that help urge shape into the sail under wind pressure. Second, there are “paneled” or “multi-paneled” sails, these are made from individual, flat pieces of cloth, but the pieces are joined to establish camber in the sail so a smooth airfoil shape appears under wind pressure.
I would agree that “single panel” sails made from TriSpi mylar would be less than efficient. Single panel sails do best if the material can deform (such as a woven material like Dacron), and mylars are not able to deform.
So now the question remains, given definitions above, what do you desire for your ODOM?
I’d say that virtually all the ODOM sails we’ve made or seen are in the multi-panel configuration, and thereby are able to provide easily adjustable, stable, and powerful shape when made of the TriSpi or PX 75 mylars.