Here is a selection from my gear shed. Okay, gear barn.
All weights are in ounces, no packaging. All lengths are the toothed portion of each blade, manufacturers probably claim a little longer. All cut on the pull stroke.
On the left are two of my MYOG efforts. Left is a portion of a bandsaw blade, cut to length, with finger indents sanded in and plasti-dip coating applied for padding and anti-slip. It does fine on 1" to 2" branches, especially green wood. Not as well on hard dead branches that I use for firewood. It's high points are the very low weight and the long length. If you had to cut a big branch, small tree or 4x4, you could, eventually.
Second from the left, I did the same thing, but to a reciprocating saw blade. It has more aggressive and sharper teeth, so it does better, although it weighs more due to its thicker blade.
The mini folding one is Coghlan's and has a very thin blade. $8. Fine for 1" branches. 2" would be doable.
The Felco 600 is 5.6 ounces without packaging, not the 5 ounces mentioned above. I got mine a few months ago. Nice blade, truly lovely, comfortable handle. Smooth locking mechanism. $30. If I was planning on doing much trail work, I'd bring this.
For the occasional annoying branch on a trail or to fuel a wood-burning on a thru hike, I'd go with one of the first three to save the weight. I've debated honing the back of the MYOG blades to have a knife on the back side - 7.5 inches fillets any sockeye salmon and handles small (to 25-pounds) halibut.
If you want either of the MYOG saws, PM me - I gave away a batch of them a year ago. Time to fire up the production line again.