The question of what ultimately are the smallest particles is of little value in big collapse process theory.

At the outer limits of the visible universe, the anti-event horizon exists, and then subatomic particle accretion mass. Sure, it is possible that as volumes of subatomic particle accretion mass become hotter, smaller and more discrete particles exist. What we are concerned with in big collapse process theory is the transition between subatomic particle accretion mass and visible universe. The smallest of the small will rarely exist inside the visible universe, except in high particle physics experiments, and random events in space. Deep inside the subatomic particle accretion mass are conditions that will always be completely inaccessible to us.