The mark of a good trainer; a well rounded and one able to work with the owners of ANY DOG placed in front of them is their ability to be more than a "one-method" trainer.
A good trainer has a huge bag of tools and a solid knowledge of the use of those tools.
Just as it is questionable for any trainer to slap a prong collar on every dog that walks through the door.....it's equally red-flag raising for any quality trainer who knows their "stuff" to say "I forbid the use of" any training tool that will prove to be and has proven to be a very effective one.
The trainers you can learn the most from and your dog has the best chance of having the solid foundation layed from...is the trainer who is willing and able to modify their chosen method of training to suit the individual dogs they are working with.
Many trainers don't "like" some of the tools of the trade...but the GOOD ONES will be able to explain their use and WHEN they are are effective...and will USE THEM when needed and when the dog will benefit from them.
To say "prong collars are outlawed in this class" not only makes me roll my eyes
but also makes me leary of that trainers limitations as an Instructor.