Is there such a thing as an "un-disqualify"?

Yes, but the held amount could be wiped very fast, because of

And thus your node will fall back to 75% level of earnings to held amount very fast too.
Then we will be forced to enable the vetting process again. So - 5% of potential traffic during the next month or two.
And pieces become deleted too every time, because your node is untrusted and pieces are still marked as lost. And of course they are not paid anymore.
So, this is the same as a disqualification but with slow clean up of the unpaid space.

I’m not sure is it a good suggestion ever.