Each of the shooting disciplines has it's own set of match rules. You can find
equipment lists on the internet. Some of the front sights have lens and
incorporate a level as well.
Some rifle buts are adjustable. If your comfort zone is to shoot the rifle
with a cant to it, you can adjust the but for comfort and still maintain
a verticle line with the target.
Agreed. I think that in Palma, the lower sight height has less effect by rifle cant than a scoped rifle where you can have as much as 2" of height over the bore which would give a more pronounced cant error. Also the repetition of the shooting position in Palma makes ot easier to master a reference point than the varied positions that can occur in the field when hunting, particularly on unlevel surfaces. IMHO