Will you cook to X° and then dip in au jus for those that like more well done?
This 'dipping' technique that Bentley mentions has worked well for me serving my guests.
I always cook any beef roast to medium rare (internal temp), since many 'beef eaters' prefer that. But there are always a couple folks who don't like to see any pink meat, even though that pink is not blood -- it's myoglobin, an iron-containing liquid protein. (Of course, we know the blood was drained out at the slaughterhouse!!)
So in order to please every guest, I simply ask what 'doneness' they prefer. If anyone says they want 'medium' or 'medium-well' or 'well-done' I just smile and say, "OK."
Then, when carving the roast I simply slip their slice into a warm bath of Au Jus, (actually just Jus, since 'Au' just means 'with'). Presto! Within a couple minutes, that reddish-pinkish color of the meat changes to a non-pink color thanks to that swim in the dark-brown-colored Jus. Then I serve it to the guest and say "here you go" and they say "thank you so much' since they're satisfied the meat is now done to their preference since it has the 'right color.' Of course, it's still that same 'medium rare' slice of meat with great tenderness and juiciness -- but not tough or dry like overdone beef can be.
I've heard from a couple chefs at 'high-end' restaurants who use this technique also whenever they're serving large groups who frequently have a wide range in their preferences of 'doneness.' Everyone gets the color of meat they want!