I've never used a Shavette or a straight for my head/dome shaving as
@PLANofMAN has state, "Straights & Shavettes are for someone who has the shaving knowledge & experience to do so without causing unnecessary major harm to your head. My advice to you is try a Injector razor, or for a safe acceptable comfortable head shave try the Gillette Guard.
It has a pivoting head is open comb with a large gap between the single blade and comb so the lather passes through the gap making it not clog and easy to rinse out. The razor is extremely light, but the handle is very long so it'll fit most hands. It shaves like a injector razor (if a Injector had an open comb tilting head) is very nimble and easy to manoeuvre in tight spots. Over the last month I've used mine for my head shaves with acceptable results
Regards- B.