I am a little confused here.
If you are using only as a transport then whether it has a " shitty DAC" or not is irrelevant.
Now upgrading the power supply is a whole nuther matter and very likely worth pursuing.
Whether you will find anybody both willing and capable of integrating an i2s board into it is a different story entirely. And if so would it be cost effective to yourself?
Good luck!
If you are using only as a transport then whether it has a " shitty DAC" or not is irrelevant.
Now upgrading the power supply is a whole nuther matter and very likely worth pursuing.
Whether you will find anybody both willing and capable of integrating an i2s board into it is a different story entirely. And if so would it be cost effective to yourself?
Good luck!