There's NO WAY that the guillotine is going to be considered acceptable if lethal injection is not. For starters, it's fairly well established that human consciousness remains for at least a couple minutes upon beheading, if contemporary accounts of the French Revolution can be believed.
Considering that there are predictions of folks eating their babies and waiting for, if not assisting loved ones dying so they can eat them . . . methinks the guillotines will be a significant but only a fractional part of the tableau of horror ahead for the world as the globalist tyranny ramps up to it's finale.
VERY unlikely. Leaving out all other possible issues with continued conciousness, by definition upon decapitation blood pressure immediately drops to zero. Which causes immediate loss of conciousness.
There is an extremely simple, non-violent way to execute. Small chamber, pump in nitrogen. As the concentration of oxygen drops, the person passes out without even realizing it.
Leave at 100% nitrogen for 30 minutes. Remove and dispose of body.