Re: Soft vs hard (correct?) kote gaeshi?
What's the purpose of kote gaeshi?
1. snap a wrist by twisting it out
2. give yourself a good connection to uke by tightening up (taking the slack out) the tissues of their arm?
IMO, #2, clearly.
Twisting the wrist out doesn't really do much to tighten things up anywhere but right at the wrist and even then it's easy to turn your elbow in to avoid that.
Folding the fingers back towards the wrist does tighten up the arm and makes a usable connection. Against the average unconnected person it will usually cause them to dip their shoulder as well, but that's neither here nor there.
pushing with thumbs = no thanks. YMMV.