Personally i place many questionmarks to the word 'traditional archer' .
In the old days a good archer was a man that could shoot with his stickbow made from Spanish Oak (100 - 150 pounds) up to 12 arrows a minute or something like that. It was a group of archers task to 'rain'down a load of arrows on the enemy.

For putting arrow rest on your bow i dont think it would push from the traditional group.

I shoot most of the times on IFAA rules.
http://www.archery-ifaa.com/

Nothing there says you can not.