My guess is, that rendering to WAV in Pianoteq, and importing into Premiere Pro, will yield to better audio quality. The rendered file out of Premiere Pro will always have undergone some processing to the audio file, converting it to AAC, if you're exporting to the MP4 format, or something else when using other video formats.
If you give Premiere an MP3 to work with, it will also process it, and the MP3 will already have been compressed by Pianoteq, therefore it's smaller in size than WAV files. You'll be processing a processed audio file, and my gut feeling tells me that will affect the quality.
Of course you can always convert to audio/video in Premiere Pro two times for the same performance, first by starting with an MP3 audio file out of Pianoteq, then with a WAV. If you find the difference in audio quality is none, or negligible, when comparing the two final outcomes, you might be fine with MP3, just to save disk space.
Last edited by TheodorN (23-02-2023 00:00)