We should send a message on https://en.wikivoyage.org/wiki/Wikivoyage:Travellers%27_pub telling the community this is being worked on with a link to the labs instance so they can play with it.
This will give us lots of useful ideas/feedback and help the extension be as awesome as possible! :)
I can translate the message to a few other languages and post it to other Wikivoyages that are using or considering using banners too, if you want?
I have left an announcement on the traveller's pub of English Wikivoyage. If there needs to be some modification and/or addition to it, feel free to edit it.