My provider uses the same IPv4 for four different customers, and it lets each one of them use a different range of 12000 ports each (of course, the random user on ports 1-12000 is the "luckiest" one because he could theoretically host a website on port 80 or 443).
But this means I can expose my Torrent client or Plex or any other services on a custom port, directly forwarded.
It works really well in my experience. The provider is Free (France).