Elm Warbow Working Hard

I've tidied it up some more and got it to a low brace (about 3"). It's flexing enough to see what's happening, to adjust the tiller some more and maybe think about the heat treating.
I've run the sides of the bow over the belt sander to even them up so that when I heat treat it I can clamp slats to the side to contain the hot air, direct it along the belly and stop it bowing onto the back.
There are some areas I'm not sure about yet, at one end the sapwood gets very thick and I don't know if I should reduce the sapwood or end up with no heart wood on the belly. Its getting to the point where I need to get the tips moving now.
Warbows don't give you much tillering time once they are braced, what I mean is, they are so stiff to brace that by the time you've manage to brace it you are 80% there... or maybe it just feels like that to me. It's all a tad nerve wracking, you can't afford to tippy toe around it, you have to pull the poundace whils ttrying to check the tiller at the same time. No good messing around trying to get perfect tiller at 60#... you'll just end up with a 60# bow.
Other opinions and experiences my vary of course, but what ever you don't listen to second hand advice!
If video doesn't come up, try here, it's better resolution on the Youtube link... dunno what's up with Google blogger today.
https://youtu.be/5PYVl88Hnu8

It looks a bit kinky and clonky in the still which is why video is so useful (just noticed the string is touching against the box of flooring stacked beneath the tiller rig, which may be effecting how the bow rocks on the tiller), you can study it at your leisure and try to see what is actually flexing. Yes the middle looks stiff in the still, but it does actually flex. It all looks stiff as the actual tip movement is pretty small, that's the big problem for beginners, actually discerning where the movement is on a wobbly stave.