Well . . . it was okay. It was partially ruined by the grill giving off propane stank and partially ruined by the lobster meat wanting to fall out of the split lobster. These things could be easily avoided and I'll offer suggests on how to do so.
We haven't used propane in years because our house has a natural gas line hook up for our grill. Does anyone have experience with propane giving food an unpleasant gassiness? The cottage we rented also had a propane oven that gave off some strong fumes when it ran. The cooktop was fine, but the oven would make your eyes water. The food from the grill wasn't overwhelmed by the smell, but you could definitely tell it was cooked over gas and the last thing you want during a meal is thinking about hydrocarbons and sulfurous additives.
But overall I am thankful for dead things giving us their flammable gases.
Step 1: Pre-grill Steam
I took the red hot lobsters out after five minutes, let them cool a few minutes and then cut them in half from head to tail. This is actually pretty easy to do (at least it was with the recently molted lobsters we were able to get). Insert the knife into the head and slice down through the shell all the way to the end of the body.
Step 2: Basting Sauce
Think back on it I think I'd have been better off making another beurre blanc and then adding hot sauce to it to make a buffalo beurre blanc.
Step 3: Grill'em
I started them on the cut side down, then turned them after three or four minutes to finish cooking on the shell. With them turned over you have plenty of nooks to deposit your butter or other sauces. You could even make a stuffing to cover this side.
Just be careful that your grill doesn't produce a gassy stink. These flames do look a little too orange for there to be a good combustion happening. When in doubt use a broiler . . . except the oven in this house kind of smelled too. What can you do? . . . saute in an inch of butter I suppose. . . . oh wow, what about lobster slowed cooked in bearnaise sauce? Wow.