I would like to see a ti clutch bolt to me that would save more weight than the cover, but I don't know if it would hold up don't know much about strength of ti vs steel.
They are already available thru Alt Impact and PCC, Alt's is far cheaper about 1/2 the cost of PCC's and comes complete with the washer, As well as the secondary bolt and washer are included. If the PCC is just the primary bolt, that is just robbery for 1/4 of the stuff at twice the price. (Maybe a PCC customer can speak to that?)
That said; with the clutch bolt being on the centerline it is essential neutral to the moment of inertia.
The further the mass gets from the rotational center line the greater the effect. Bang for your buck!
For a visual of that, take a bike tire and a car tire of the same diameter, which would you rather spin and keep spinning? Additionally the larger the mass and the further it is from the rotational center line the greater the gyro scope effect is which ultimately will resist rider input and prefer to follow Newtons law "that once in motion it wants to remain in motion" the other half of that is "unless acted upon by an outside force". Which is You the rider, the larger the Gyro effect the harder you have to work to overcome that and get the sled to do what you want it to do. FWIW