That suggestion, though a good idea, is beyond what ULX was written to be.
ULX was never written to be all things to all people. ULX was written to be a tool used to make administrating a server, that is, its
core functionality was to make it much easier to ban/kick/punish and even reward players.
For instance, banning a player from a Source server normally requires, from console, "banid <time> <STEAMID>"
If you don't give time, it errors.
By the time you have run 'status' to get the steamid, and then typed in/copied the steamid, the person has probably already crashed your server for whatever reason you were going to ban him in the first place.
BUT, thats where ULX comes in. From chat, !ban <partial name>, or console ulx ban <IT AUTO COMPLETES, or partial name> <time>
If you leave time out, it adds it for you at default.
Time saved. Simplicity at its best.
In the case of your suggestion, an anti-spam script, ULX wasn't written to do that.
HOWEVER, that's where releases and our module system comes in. Things can be written to work with ULib (our library), or even interact with ULX, to do various functions.
As for your time delay idea, I believe you may be looking for something like
ASpam.
It was written by Jay before he joined our team.