You should only have one active control channel at any given time.
Only lockout the current control channel.
On many systems the channel will change everyday so when you pickup the data from the control channel, lock it out and unlock the previous locked out channel.
You will also pickup all voice traffic on the system. There is no way to track or lockout talk groups on a conventional scanner.
The
system that I stream is a five frequency system and can easily be monitored on a conventional scanner (at times I even use a Yaesu FT60R), but if your trying to follow a 28 frequency, county-wide system, with thousands of talk groups, it may be more difficult. (I use a BCT15 for the feed as I don't want to stream everything).