The problem isn't the valves being titanium, it's the cam profile. CRFs are notoriously hard on their valves. The ones that don't break will recede instead. Yamaha didn't have either problem with their YZF's titanium valves. The YZFs are widely regarded as being more durable, more powerful, and lower maintenance than the Hondas. Why Hondas are more popular baffles me.
Are the back-side of the cam profiles the same with the Honda and Yamaha?
I agree with you PD on the seat pressures. In fact I don't normally run over 40lbs seat.
Sorry I been gone, I could have helped alot. And you could have gone bigger.
I think CRS and I, and most certainly Roadkill can handle the seat pressure inquiries.