I’m not sure if this is technically possible, but…
One of the discussions about the active collator and delegator set led me to a thought…
As you know, if a collator drops out of the active set, delegators get into an uncomfortable situation where they either have to wait and hope for the collator to return to the active set or do a revoke. Wait 2-7 days for this operation to complete and then return to the portal to re-delegate tokens.
What if you create a new feature that allows you to merge the 2 operations? I mean, the user could choose who to delegate their tokens to during the revoke operation. Instead of having to remember 2-7 days later.
When you’re steaking tokens, you want to make any transactions with those tokens as infrequently as possible. Steaking involves long-term storage. You want to put the tokens away and not have to come back and check to see if everything is okay.
And you certainly don’t want to wait until a long operation like revoke is completed to stack again. You also have to remember to do it. I can tell you from experience that I was missing 3-4 days before I remembered that I had tokens idle. And it was not very pleasant.
Well, it’s just an idea, I don’t know if this implementation at the technical level is possible now. And maybe you will think that such feature will be superfluous 
P.s. While writing this post I was thinking that it would be great to have “Safe Collator” feature, to automatically redelegate tokens, in case your collator dropped out of the list… 