We have a UI requirement, where users need to be able to create several ranges from 0-1000.
Without overlap (including overlap from other parent records)
So, parent 1, has range 0-10, 20-30, 50-55.
Parent 2 is being created, the values parent 1 has chosen are to be unavailable.
There could be dozens of ranges per parent.
Free-text, though my preferred option, has been shot down.
I don't like a long list of 1000 numbers, where you disable already selected values, and allow them to pick all the values that are allowed. But it's not "range based", so I don't like it.