Hello Andrews,
Unfortunately there is no way to disable the logic that mutes both the ADCs and the DACs when the PLL is unlocked. I agree that this should not be the case but it is.
Certainly one way to get around this it to split up the functions onto two parts. The AD1974 for the ADCs and the AD1934 for the DACs. The benefit of this solution is that there are now two PLLs so each part can operate with only using LRCLK or with a 12.288 MHz MCLK. But, it is two parts instead of one and its associated decoupling and board space.
Thanks,
Dave T