So far, the compatibility of AI1EC with Polylang seems to work better than "the other ML plugin".
The thing I am seeing though, and if you can help me around this I would so appreciate it, is that even though I am translating an event by clicking the plus sign and editing the translation, it gets added as a separate and independent event. When viewing the calendar or the widget, I get BOTH versions of the event.
I have really appreciated your working with the ML plugin developers. I hope we can do more here than say "it's the other one's issue.
I'm happy to post the question in the Polylang forum as well :)