spdif usable as digital stereo return?

  • i got a tc electronic g-system with a spdif-output only (no input).

    is it possible to put the g-system into a stereo-loop (mono send, stereo return) in the kpa's x-slot using the analog send and the digital spdif as stereo return?
    this way i could avoid da/ad-conversions with its' latencies.

    doing it all analog would use the following conversions:

    ad: kpa-in
    da: kpa-x-send
    ad: g-sytem-in
    (da: g-system-out)
    (ad: kpa-x-return)
    da: kp-out

    if all conversion stages were similar in latency (1,6ms), it would sum up to 9,6ms of overall latency. :S