In any case, to wrap up this thread. I managed to set this up with sysctl. End result gives me a tunable per netns (which modparam would not), and thanks to the RDS reconnect infra, can be done dynamically at any time, not just at startup. And it is more compact than a daemon-y solution.
I'll send out the patches later this week after some more cleanup and testing. --Sowmini However, it would still be nice to know exactly what distribution issues come out of modparam.