That's a cool one, didn't know those exist. Probably not ideal for me when I ride in the rain and my bike gets left outside at work but could work for those in dryer climates (or does the original rubber cap stay securely on that new lock?).
I faintly remember the rubber cap on the old lock. You could probably find one like that, but this lock is sealed pretty well (I might have added a rubber piece to ensure that, but can't recall as it was so long ago now). I've never had a probably with water leaking in (and I've ridden in the rain as well and had the bike on my truck when hauling an it got wet for hours).
As I said, it's a minor investment and if you buy and it doesn't work you can send it back. (I have done a few locks like this for my Jeep, toolboxes, etc - things where I just didn't want to have to fish through my already oversized key ring to find the right key. Seemed this was just about the best case for that issue and I'm surprised that Zero didn't offer that as upgrade / accessory, TBH.)
-S