MSGI: Two things:
Number one: I've been the chief champion of selling half on the double and I abdicated that theory TODAY... and I'm kinda involved with PSL10 - and SSK doesn't adhere to the theory either. So, if it wasn't logical in the past for PSL, it SURE wouldn't be logical in the future.
Number two: If a person really wanted the ability to do this, they should be arguing for a DD breakup. That's what I thought you originally meant because it never occurred to me anyone was asking for a spit of a single unit. That MIGHT be a change that would be worth considering and would allow a person to sell half whenever they wanted and keep the other half for whatever reason they want. But, even with the DD, it's unlikely that we will want to change the rules. Everything seems to be on cruise control after 10 PSL's.
Len