Correlate information between tracks

[nawatts]

When hovering over a tracks, show a line to make it easy to match up information between tracks. Preferably, show a marker next to the line with information about features in that track at the hovered location.

[nawatts]

Have a way to lock this in place to avoid movement while scrolling? Or better yet, be able to add/remove multiple markers.

[nawatts]

Allow setting a marker from a button in a variant's table row.