Man, I like how your mind works!
As I had my fair share of discussion with @howard and @gio about this, maybe @fennario 's analysis explains it all.
For my List of play-along songs with synchronised tabs on Youtube I never intended to create sheet music, but synchronised tracks.
If @fennarios analysis is right (which it is), this explains the variations in tempo.
I will take the most discussed songs and run those through RipX to see if it finds tempo changes.
And than let’s rediscuss it, as it is big fun 