I am going to suspect they can but too many details to say for sure. Years ago ISP routers were very inferior to other routers mostly because they wanted to keep the costs down. Wifi chipsets have been produced so long they have gotten very inexpensive. You many times see ISP routers using the same exact cpu and radio chips as many of the better known routers that have similar specs.
The dirty secret with this nat bypass feature is if you buy a really fancy router and are going to use something like firewall or parental controls the traffic must pass the router CPU to able to be analyzed so this feature must be disabled. You end up with the high power router running slower than a cheap router that does not have fancy software...