Yep I’d say thats the issue. Some of the pants I've worn over the years have a more slick material on the front and around the pockets - snags less when they fold or ruck and side benefit is they shed chips/ sawdust better. But not sure about if you’d lose some breathability maybe.
As for back pockets - I stand firmly in support of a zippered pocket (optional extra at slight additional cost?).
These are great pants as is and it is huge with me to have someone other than a large mega-deathstar corporate octopus makin’ neat stuff.
Keep fighting aridity and disenchantment!
All the best,
e
edit, on thinking about this more: Pete, forgive, I should provide maybe a bit more context to the work too. The forest we were felling/ limbing/ bucking in was mature black spruce, about 45 - 55 ft high but with huge amounts of dead branches, slash and smaller noodles in the understory. The dead branches average 1/2" to 1" diameter and when broken off, tend to shear at a 1"- 2" or so angle leaving a sharp pointy bit. Thats how the pocket corner met it's end - I was limbing/ bucking and one of these dead ends got me. These trees are nothing like what you see Dave Coleman or Ace Tree work on in YouTube videos - large spreading deciduous. Instead we do daily penance working on all manner of tightly packed dead standing pitchy toothpicks that limb tie at every opportunity (hence the fire hazard to homeowners). Sap removal is also a major issue on clothing and gear (98% isopropanol). Hope this helps a bit. Snaggy is a big deal in this kind of work.