In most cases, having the current zoom level visible in the URL bar is useless information - and displaying useless information is probably bad.
I can see an argument for showing extreme zoom levels, very low or very high, so users are aware why a page might look weird. But indicating if a site is scaled to 90%, 100% or 110% is useless information, in my opinion.
So, my suggestion is: please remove the zoom indicator from the URL bar - or if you think you need to design for worst case user at least give others the option to remove this UI element themselves. Right now there isn't even a config flag for this. 😞