kk74, as you've discovered, the number of OpenVPN clients in the RT-AC3200 router was limited to only two clients/configs in June if memory serves, to save on space in the limted NVRAM on this model, since it doesn't have as much as provided in the other models. Supposedly in the Asus new official build, they've increased NVRAM to 128k, so you could try reverting to the stock FW to see if that suits you (I like v380.68_4 so will stand in place for a while). RMerlin may be able to bump the number of OpenVPN configs/tunnels upward perhaps, -maybe- when the code/FW from Asus becomes available but it still be while, since all of the new code has to be worked into his fork, tossing out the bad bits and bytes along the way; just informed speculation on my part and is not an official take on what is/isn't being done. I haven't ever been inclined to use the factory builds for years, they're always so buggy..
The info on the last FW build that uses more than two client/configs is in Merlin's change logs, so do read that and see which build you will need if you decide you want more than two Openvpn configs, so you can revert to that one. Merlin dropped the number of configs to two (the last numbers of firmware that offered more than two configs end with '66.6'). If you do revert, please post your results and experience; I'd be interested to see if my 3200 can run 3 concurrent tunnels adquately. If you run a lot of scripts, you're probably going to overload the NVRAM quickly. The new official Asus stock FW supposedly increases the NVRAM to 128k. I'm able to run two concurrent configs, but can't imagine it would run 4 or 5 OpenVPN tunnels well at the same time. That said, it would be nice to have an extra config set up and standing by so you could turn the second active config off and the third config on,without having to erase one to use a different config/server. Cheers.