re: Does that mean that if I was going the multisite way with a tool like Multisite Language Switcher I could have Connections running in a multilingual mode?
Maybe… comes down to how that plugin manages translations. If it loads the appropriate plugin translation files for the selected language per sub site, then maybe, yes. You would “simply” create the same entry multiple times, one for each language on the corresponding sub site.
re: Have you had any experience with that setup?
Nope, sorry I have not.
re: Am I right to understand that I would need a license per language?
Honestly, not exactly sure because I have not tested how license activation works on subdomain mapped multisite install. You will if each language was a separate domain. I think if you do subdomain mapped sites you’ll only need a single site license. Either way, in this specific use case I can and would manually activate the licenses on the subdomains for you so you would only need a single site license.
Hope that answers your questions thoroughly!