You can try it anyway ¯\_(ツ)_/¯ Backup all your stuff and give it a shot, worst case you´ll have to wipe the browser cache. Other than doing that, your best bet is to either find someone to port it for you or port it yourself.
It does convert to C3. But only to the c2 runtime, the c3 runtime can be added with -c3stub but it will be non-functional. So you´ll need to do some work there anyway.