Additional option to "Someday" - later?

I'm a user with a large number of tasks (hundreds), "Someday" is a mess and isn't that helpful for me.
I would personally favour an (optional?) additional category of "Later".
So you end up with:

• Inbox (Capture)
• Today/Upcoming - Time blocked tasks
• Later - Non-dated, but actions that are "next up" just pending a date.
• Someday - Things to keep in mind, but not necessarily something that will happen (similar to "someday/maybe" in GTD).
  At the moment, the only option is to either date something (and then continue to change the dates, which is heavy administratively) or to use "someday" which then leaves nowhere for "these are things I don't want to forget, but am unlikely to get to anytime soon"
  Having this as almost a "backlog" within the "upcoming" section would then also allow for enhanced planning processes
  Hope that makes sense!