In my case (although I have not yet flown with APP3) the ANC works great, however, transparency mode (and adaptive mode) have issue with a noise. In a silent room I hear quiet noise in transparency mode (not present in ANC nor in "Off") which wasn't present in APP1. I tried different tips

Also, transparency mode felt more "natural" in APP1 in comparison to APP3. Currently it feels like a downgrade from APP1 (unfortunately my pair of APP1 broke recently), because I used transparency a lot and it feels worse