You do know part of why this system is built like this is to encourage you to run out of space. Anything $E will do to give players more space will hit their income from retainers.
With the retainer "system" in the background, the only thing $E wish to do, if anything, is to clog our inventory even more. It's a perfect and elegant way to make players realize they need retainers than just push them in their face.
That said, I liked the OP and wish it'd happen, but don't get your hopes up.