Yep. I use GMail and Safari on iOS. When I open links from GMail, every so often it shows a popup saying "would you like to install Chrome and open this link with Chrome instead of Safari"? It only appears intermittently, not on every link (fortunately), but there's no way to disable it.
Yes, it's disabled. Evidently the two options are "ask me each time" and "ask me intermittently"; there doesn't seem to be an option for "don't ask again".