I use a Sven saw to informally clear trail in spring hikes with Scouts.

There are some improvements on the wire saw to consider besides bending it into a bow: a couple years back someone made a compact saw using sturdy chain saw chain and well constructed loop handles on either end - I bought one of those and it does indeed cut really well through tolerable sizes somewhere between lopper size and 6-10 inch logs. It folds down into something the size of a multitool or two, so its pretty compact and doesn't have any of the disadvantages of heat or flimsy construction. And I know we've used it a few times, usually setting a couple scouts to saw off a downed tree, and the actual cutting is a little slower and more awkward than the Sven - but the chain saw chain model hasn't broken and it definitely works. So they got that part right, but basically this is in competition with my trust Sven saw which has been lightly trimming trails for 3 decades now (I think I might have kuyped it from my Dad actually, who cleared trails and Left Lots of Trace way back to the 40s), so it doesn't really get used much. And if I ever used it a lot, I'd have to consider sharpening, which may be a little tougher on detached chain saw chain than I'm used to on my Stihl.

I don't remember where I got the chain saw chain model but I think it was local to WA somewhere, interested folks could look for earlier posts on this forum as I'm pretty sure we discussed it.