I'm a bit spoiled by having a lathe. I've ridden a bike with a crack in the lower headset seat for several years. But I machined a steel collar to press fit to go around the outside of the head tube. Top headset seat takes less force than the lower, but I still don't think I'd be comfortable passing a hose clamp repaired bike on to another rider.
The clamp in the pic looks a lot sturdier, but it has to be a good fit to work as desired.
Either way, building up on an obviously damaged frame is something I'll only do for own use, and if I have all the parts already.