I'm not sure what your particular problem is with respect to using it on other Macs. The current OS X drivers do not do the update, and I mainly use the ZIP drive between my vintage compacts and OS X Macs. If you are using it on other vintage Macs, just make sure that the ZIP Driver installed on all of those Macs is 4.2 - I've yet to see a Mac that didn't work just fine with the 4.2 driver. That's how I've set up all of my Macs, so no accidental updates. If you need the ZIP Tools and extension, then make sure you have the 4.2 version. I've been meaning to make it available for download for some time now, but haven't. Not even sure where it is at the moment. But I found it with a short Google search.
Now I suppose if you are using it with random vintage Macs you encounter in the world, then yes, you'll run into problems. However, if you reboot the Mac with the ZIP extension temporally disabled, I believe this will prevent the update. It's been a while since I did this, but it may be the work around. Also, you can lock the ZIP disk so changes cannot be made. I seem to recall using this method back in the day, so if I stuck it into a system that had a newer driver I would be OK. Once inserted you can copy a 4.2 driver from your ZIP disk into the extensions folder and reboot, temporarily disabling the newer driver on that particular Mac. Always keep a copy of 4.2 disk tools and driver on the disk for just such situations. Or, as Trash points out, as long as you are rebooting, as long as the zip drive is connected, all you have to do is bring up extensions manager and temporarily disable the ZIP driver, which allows the drive to boot off it's own driver without fear of being updated by whatever is installed on the computer. And of course if there's no ZIP driver on a particular Mac, you'll have to reboot anyway to bring up the disk, or even plug in a ZIP drive.
You can also use ANY system on a Zip disk, back to 1.1, as well as format the disk MFS. Check out this tutorial - http://www.mac128.com/zip