Hello sportshoes,
I haven't tried adding more than 5 port forwarding rules at a time, so I can't say for certain that the new firmware changes anything. I'm running bridge mode and have a pretty amazing router hooked onto it, so I haven't had the need to do this. I do recall you can forward a range of ports at a time, so if you have a lot of stuff that you want NAT'd to the same internal host, you can consolodate that way.
As for the new firmware, as far as I know, it was to address the immediate concern of stability in bridge mode, and nothing else, so I doubt the update will do you any could.
Sorry I couldn't be of more help.