Just a little idea that occured to me. What if doff slots were scaled with ship crew. The more crew you have, the more doffs you can use at the same time.
Short answer: It'd probably break the DOff system so hard it'd be completely unfeasible to add.
Longer Answer: DOff's typically have exponential returns in their investment, provided they have synergy with your ship. It's like expanding or contracting the rosters on Crew-size would lead to all kinds of really weird problems, with anything less than 3 DOff's leaving most any ship critically starved for slots, and more than maybe 8 or so leaving ships struggling to fill out their roster with truly useful DOff's.
Also, do I know you, or did you just randomly pop-up out of the ether?
If you feel Keel'el's effect is well designed, please, for your own safety, be very careful around shallow pools of water.