You will likely have it fail. OTAs frequently check the /system directory to make sure the expected files are there prior to update. OTAs will likely not flash on a custom rocovery as the firmware portion will not flash from that. Your best bet.. S-off now.... flash stock... take OTA. Then flash TWRP back and flash your custom rom of choice. That will allow you to upgrade to the latest firmware and still run a jelly bean rom. On that custom rom you will still get a nag to update the OS but you can find ways to disable that until the developer updates his rom.
IF you simply wait for him to update his rom, you will still need to manually update the fimware in RUU.