Your confusion may come from the SE availability. Years ago, Jim developed a Signature Edition for the CS2.4. Most of the upgrades were cabinet related, but there was and is a crossover upgrade which replaces the 2 feed caps (bypassed with styrenes) with 2 ClarityCap SAs, unbypassed. SAs were best of form at the time. The sonic improvement is noticeable. Some folks buy those caps from Rob.
Our upgrades are considerably more extensive and expensive and not yet finalized.