One partial "work-around" would be to use zero delay on the system, but use a one or two second hold. With the channel programmed "both ways", one entry analog, with the PL tone or DCS code, and the other entry digital, with NAC code, both modes are covered. Your "delay" is covered by the system hold time, instead of the individual channel delay.
I do much the same thing on Texas DPS where base transmissions are on one frequency, but mobiles are transmitting on an entirely different one. The bases are not often set to "repeater" mode, where both sides of the conversation are heard. In the more rural areas, where mobile repeaters are used, you do hear both on the same frequency, so a delay would work.