Airburst rounds like the 40mm 3P are also used against air targets as they don't expand their shrapnel just downwards but all around. And it comes with a proximity fuse.
The 30mm KETF gives you some 150+ wolfram darts expanding right in front of the target. Should be quite lethal against air targets (including light drones), troops in the open, and lighter structures. I am sceptical of it's after penetration effects against heavier structures, though.
Spike instead of Javelin gives you this lovely attack without LOS capability.
As for calibre. While 35mm or bigger offer several advantages they also comes with a hefty penalty in stored rounds. For example the CV9030 stores 400 rounds while the CV9035 only 280.
When one sports a ATGM the need for heavier calibre also diminishes as the cannon doesn't need to be able to handle heavily armoured targets all by itself.