As usual, the best work is in the small details. Here is the left hand table on a Super Action 80 II I just overhauled in my saxophone repair shop here in Seattle. As you can see, the Bb mechanism in the first photo is level with the table. Repair techs worth their salt everywhere are always going on about "leveling the left hand table." And they're right. The table must be level to facilitate navigating the the three lowest notes on your horn. But in this Selmer design the Bb needs to be tilted.
When it's not, its stroke bottoms out at an angle too great in relation to the B and C# spatulas. This makes navigating the table impossible without awkward extensions of the little finger. If you pick the Bb spatula up, as it is in the image on the right, you decrease the final angle: Follow the stroke in your mind; Remember, we're not changing the height of the Bb key cup, so the pad cup strokes the same distance, but will now bottom out at a smaller angle in relation to the B and C# spatulas. Reducing that angle reduces the work of the little finger which facilitates a quicker, snappier, and far more comfortable action.
As with all fine saxophone repair and adjustments, there is a balance; If you go too far with this adjustment, it makes getting from C# to Bb very cumbersome.