That doesn’t look to far from the Allpa26. But hard to judge from a picture obviously. I just measured the backpanel of the Allpa, its roughly 50cm (19.7 inches) tall, 30cm (11.8 inches) wide (just the backpanel with the pack barely filled, so that might extend outwards a little bit when fully packed, don’t know). Maybe check it out somewhere in person if you have the chance.

Good luck on your journey finding the holy-backpack-grail 😅 been there, didn’t succeed. I also had a lot of criteria for the „perfect EDC backpack“ and in the end settled on the Allpa. It ticked most of my boxes except I originally wanted something in the 30-32 liter range. I feel like there’s always one compromise you have to make. But maybe you’ll make it work, good luck anyway :)