Please enable audio input from the ACCY line input while the MIC input is selected. This is a necessity to play recorded voice messages where the input is on the ACCY connector while the front panel mic is in use.
Another aspect of this will be a way to set the gains for each of the inputs. For example, on the K3 when you use MIC+Line you have to set the input as line in and set the gain, then change to MIC input and activate mic+line. From there you can adjust the mic gain as necessary.