I have used this for a while:
https://www.511tactical.com/rush-moab-6.html Plenty of pockets, carries a small slr camera, mini tablet, garmin inreach, phone, etc.
Will fit under a BK seat...
5.11 RUSH MOAB™ 6 SLING PACK 11L
also has a compartment for CCW if you are working in a high threat environment... 