I really like the Windows 10 feature that after clicking letter it zooms out and list of letters is shown. I also found out you can reach this list by touch gesture (like if you want to zoom out that page). It's really like this and it seems faster and more precise that using smaller alphabetic list on the side. It might not be a bad idea to add option not to show this side alphabetic list.
Tablet: Surface Pro 8,
Other: Strich BT-FP2, USB-MIDI connection to Kurzweil Forte 7