I'm not sure if this is what the OP was asking about or not -- but I'll put this out there.
FWIW, Here's what I'm seeing locally.
A commercial operator has a single VHF NXDN repeater set to SCAN all of his programmed channels, all using the same TX/RX frequency pair - just different modes and/or squelch codes.
Example:
Ch. 1 NXDN same freq pair, but TX-RX using RAN set 1
Ch. 2 NXDN same freq pair, but TX-RX using RAN set 2
Ch. 3 Analog same freq pair, but TX-RX using PL-Tone set A
Ch. 4 Analog same freq pair, but TX-RX using PL-Tone set B
Ch. 5 Analog same freq pair, but TX-RX using DCS- Code set A
Ch. 6 Analog same freq pair, but TX-RX using DCS- Code set B
The repeater SCANs all of it's programmed channels. While scanning, the first signal in, whether analog/NXDN and with whatever PL, DCS, or RAN code it has, activates the repeater in it's respective mode with the appropriate squelch code. Post conversation, when the repeater drops and the prescribed wait time elapses, it resumes SCANNING all channels waiting for the next signal to stop the SCAN and start the process all over again.
I'm guessing that all the radios on this system might have Busy Channel Lock-Out enabled so a user can't key up if some other mode/squelch code is using the machine. I'm told that he tells his customers to watch for the green Rx light and if it's off, then they can Xmit.
His customers aren't big-time yakkity-yak groups, but he keeps them all separated this way.
To keep some of the Baofeng Bandits off his system, he appears to use a different squelch code (PL, DCS or RAN) for input & output; making it difficult to discover the correct code for the input side of the channel.
Example:
Ch. 1 NXDN same freq pair, but TX-RAN = 10, RX-RAN = 40
Ch. 2 NXDN same freq pair, but TX-RAN = 20, RX-RAN = 50
Some of those Bandits are too lazy to hunt down the correct input codes.
Customers that want the digital features (and are willing to pay for NX- radios) are on the NXDN channels separated by different RAN codes. The rest are analog, separated by a different PL or DCS.
[Off topic, but I've noticed that the usable range of his NXDN exceeds the usable range of analog from the same repeater.]
From what I can tell, he has at least six different channel configs set on that one repeater/freq. pair. Some of his customers are primarily 'weekday / daytime' operations and others are 'night / weekend' types so there's probably not too much conflict.
I hope this addresses your topic.
Good day.