I've 3 issue with it:
1 - It will not charge with USBC PD charger.. you need an additional cable / charger.
2 - It is not detected on my iPad if not powered down and up.
3 - The maximum volume is lower with iPad over USB (BT is Ok) even with max volume set.
I hope topping will fix at least iOS issue. And if it can fix the charging one it can be a real replacement of my NX4DSD.