Manually adjust beat grid for variable BPM tracks

[StupdNerd]

Feature Description

Hi Guys and thank you for all the development so far.

All in all, coming from Serato, I am very happy with Mixxx, the features it offers and its open source nature. For me at this moment, there is only one thing keeping me from using it full time, and that is the beat grid, more specifically, its adjustment.

As it is right now, the beat grid can only be manually adjusted for tracks with a constant BPM using the beat grid adjust feature. However, there are no tools to manually account for changes in BPM. Therefore, for those tracks, we have to rely solely on the beat recognition, which is sometimes unreliable. Therefore, I would love to see a feature allowing manual usage of the flexible beat grid, for example like it can be found in Serato.

[ronso0]

Welcome!

This has been requested somezimes already and there is work in progress, I think the most recent PR tackling this is #13330 (or some related PR, admittedly I lost track...)

Ill close this since there are a few duplicates.
Thanks for taking the time to file this request!