Brian , Gibraltar is correct.
Mosaic consists of two parts. There is the software control interface which runs on an Android or iOS device. It does not handle any sound data processing but sends commands to and receives and displays metadata information from the hardware/firmware part in the network player ( Vivaldi Upsampler/Rossini DAC or player/Network Bridge) which is where the music data is processed.
So as the control app does not handle the music data different versions cannot affect sound quality.
In fact you can run an Android version and iOS version simultaneously so long as you do not try conflicting commands. No reason why you should but you can. So if you tell the Android version to play Album A you will see that the display on the iOS version will then also show Album A is playing as both are receiving the same metadata from the network player.