In my experience after assigning a keyboard key to the tap tempo action, I created a tempo track and hit play. If I try now to tap a new tempo, VSTlive freezes.
It also freezes when you i.e. type letters on the tempo display on the main window (random though) … looks like a bug
Tap tempo function is quite hidden in the actions screen. I’d suggest to have a menu/link next to the tempo display in the main window, showing the function is activated.
Oh maybe I see it wrong but I thought there was a difference between audio tracks and midi tracks as far as tempo adjustments concerns. In general tempo adjustments in midi are straight forward while in audio warping can become an issue.