And I think with any bit contact should at some point be released... otherwise where is the horse's release of pressure coming from to tell them what they are doing is correct?
Do you just drop your reins when in the ring? You give minute releases within
the contact to reward the horse. You don't drop the contact. Riding on contact is a constant game of give and take. Minute releases, minute half halts. It isn't a constand 'hold'.
In regards to the mule bit - if your students need them to control a hot horse then how do they have the finesse, timing and ability to use them properly without causing discomfot intentionally or unintentionally?
I find that those riders who have the finesse to use a harsh bit for the betterment of the horse are usually those who don't need