You are making a lot of unjustified assumptions here.
First of which that the scanner has to scan talkgroups. IT DOES NOT. In ID Scan mode, the scanner does not increment through all possible TGIDs looking for traffic. There are millions of possible TGIDs, and scanning them all would take over 58 hours if the scanner scanned them like conventional frequencies. What the scanner does instead is listen to the control channel. When a user keys up, the control channel broadcasts the TGID and the voice channel that will carry the traffic. The scanner looks up the broadcast TGID in its programming, and if it finds a match, it displays the match while playing the voice traffic. If there is no match, and the scanner is in ID Search mode, it displays the TGID as unknown and plays the voice traffic. Limiting ID Search to a range of TGIDs would actually slow the process down, because the scanner would have to do a second lookup to see if the TGID was within the search range.
Second, if you knew the system well enough to know with certainty the number range where unknown talkgroups of interest would be found, they wouldn't be unknown, and you wouldn't have to scan for them. You would already know where they are. If you don"t already know what a TGID is, you should never assume you know what it will be, even partially.
What you are asking for is pointless.