I'll try to help Lepton's case here...
IIRC, to restrict / unrestrict a ship, there needs to both be the shiplist edit, then a restart, for the change to take effect. Therefore, this would reasonably restrict the amount of times that the shiplist would be edited / changed, probably to coincide with DB cleans.
What I meant by the "as long as a ship is on the OOB, it's unrestricted" bit: The ISC currently has CCYs, CVLs, CVs and CVLPs on our OOB. Whether or not all the ships are assigned shouldn't matter, until each and every ship is destroyed it should remain unrestricted on the shiplist. This way, the ISC could swap their ship around without requiring further Admin interference. The only problem would be when a new ship was ordered (like when I order the CVS or something like that), then the Admin team would need enough lead time to make the shiplist edit, and have it cought on a reset to kick off the build round, or if all of a ship-hull (say all the CVLs) were destroyed, then we'd be stuck seeing them in the yard till the edit / restart.
Then again, keeping track of all this & the need to keep errors down (would you want to be the race stuck a day or 2 without access to your special ships cause the Admin unrestricted the wrong one) makes me tend to agree with Dizzy there... (too much tracking, no playtime...)