Don't forget the good ole pull test. Set some ropes in the top from the ground and pull laterally to your satisfaction.
Or
Set a pull line and negative rigging. Cut the notch and back cut, leaving the hinge a little big. Maybe even a wedge to hold it upright. Get out of the tree and pull it...
I must have bought the wrong Cardos, because mine were absolute trash. No range, had to yell to get the mic to register anything. Yes, we played with the settings in the app. Straight garbage units.
Don't remember which ones I bought, they got retired to the trash can after 2 days.
I suppose it's a lot better than cutting too short. Trees drop limbs and leave 6" splintered stubs all the time. Is it best? Probably not. Is it harmful? Probably not.
Nothing's ever 100% with trees, and I think they can tolerate a lot more than Arborists give them credit for, but a lot less...
Take the splice end of your line, running bowline choked to the spar. Biner in splice. Take the tail from below your zz, hitch, etc and clip a bight into the biner, descend. the friction from the 2:1 disadvantage lets you descend easily and it lets you have a retrieval leg to pull when you get...
If you're busy, stay home. Not worth pissing off regular customers. You'll need contacts, hookups, carry a couple weeks of fuel and supplies, be prepared to sleep in trucks with no showers/toilets and have access problems. You can't get supplies, you can't get parts and if something breaks you...
Don't cut just to do something to the tree. A major cause of tree mortality in the urban landscape is over pruning. If it doesn't need something to benefit it's own health or achieve a goal for the owner, leave it alone.
I'll carry a foot lock prussic for several uses. One is a secondary lanyard. Learned it from Chris Coates. Girth hitch to one hip D and use a biner on the other side. Short enough to not need an adjuster.
We use Steve a lot at my company. We're small (2 guys) but with the right equipment. This mek absolutely crushes big and hazardous removals that I wouldn't have the manpower for otherwise. I've had 4 and 5 crew members before and absolutely hated it. Employees suck. We show up with the two of us...
We could always meet somewhere and rec. I think a solid foundation of climbing spikeless is essential. Its relatively easy to walk up a trunk and strip out limbs, but to to it safely requires some rope and knot work. Or if you want to come out on a removal day I'd definitely pay you to come work...