Here's some pics of a traverse we did in Hendy Woods back in 76. Over 40 feet across and about 200 feet up. Showing my friend Andy half way across. And yes, those are spikes he's wearing. It was all old school back then.
That's a slip hook for chain, weighs in about a pound. Thrown over a strong limb and followed by a little fiddling to hook back into the rope, offers a fairly secure anchor to get where you want to go. Just like setting a choke. Though I didn't use the hook at the Hendy Woods climb, I do quite a bit working at heights where the trees are further apart than I can use a throwline for setting a rope. All of which is planned out before going aloft, of course. Otherwise I don't pack that thing with me. Situations have come up where I wished I did though.
Where a tight crotch presents itself afar I've simply thrown a wad of rope over to jam into the crotch, and occasionally even a stick. In either event I'm always securely tied-in by my primary support. And yes, I've gone winging back from whence I came a few times. Jam knots pull out, limbs break, but never has that hook let go.
My two cents,
Jerry B