Tempo Mode; Standard vs Modern (Accurate)?

[Skaven]

I ran into small issues a while ago, and need to check a few things.

I recently switched my song to accurate BPM (so that the .wav files would be easier to edit in sample editors that support BPM values in their ruler), and I think I noticed:

1) In Modern tempo mode, only the Txx command affects the playback speed (BPM) of the song
2) Axx no longer affects playback speed, but it still affects the speed at which the envelopes play

Did I get it right?

Player -> Approx. Real BPM does a pretty good job iin finding the Txx value I need to use, if my sub-tune has an exotic Axx + Txx combination, but if I have multiple sub-tunes, I'll have to switch the Tempo Mode quite a few times. 

[Saga Musix]

Your observations are correct, Axx just sets the number of ticks per row, but the duration of a row is solely based on the Rows per Beat setting and Txx.

Since sub tune/sequence handling is still far from perfect, getting the correct BPM approximation is indeed quite a hassle. I suppose per-subtune default settings would help a lot, but that is currently not planned (at least by me).