Have you read the instructions at communications.support? It does work. Safest way for me was to use my channel knob as zone select and then put the trunk zones in zone 17, 18, 19, etc. That way as long as I didn't have a zone button programmed I could never accidentally switch to a channel to affiliate. I just reference the talkgroups I wanted to hear in the scan list, which was easily edited. I had zone 16 as my scan zone and then used RX only conventional channels as my scan list placeholder channels.
I found I preferred to stick with the zone knob because I typically sat on one channel all the time anyway, and I set the left and right soft buttons as CHUP and CHDN. It also made more sense since I could have more than 16 channels in a zone. And with last channel/zone checked, I didn't have to scroll the list every time I switched zones.