I'm sure that those changes CAN be used as switches, but they would be less effective than a simple shuttle pass.
I would say that depends on how much time a person has dedicated to mastering any of the mentioned sleights, how natural they look and then creating proper motivation for the movement.
Take Roth's flash change for example- it is an obviously "magical" movement- flipping a coin over onto a hand while waving the hand over it? Who is going to do that to toss a coin from one hand to the other?
There isn't a wave in the Flash Change (at least not in the text; Roth might wave his hand in the videos). It *should* look like you just turn your hand over and the coin falls out. The fingers slightly curl (but look natural) and the now empty hand drops to your side. I wouldn't do this from one of my hands to the other hand, as again "What is the motivation to do that?" Instead I would ask them to hold out their hand and just drop the coin into their hand, then let my hand drop to my side.
I will agree that using a flash change in more advanced and more complex in the terms of logistics.
I assume that Pyris uses a coin which helps a bit with the fire part, but can't be handed out for examination (which provides the need for a switch) and has a good side and a bad side. Again, I don't own Pyris, so I don't know the method. Another option would be a one handed "crimp" change. I did a quick search and found an example video on you tube here:
http://www.youtube.com/watch?v=Wz-jfRWE4BU&feature=related
...it is being presented as a color change, but there is no reason why it would have to be presented that way. After you "blow out" the coin say, "Here take a look..." (and start to hand it to them, half way through the motion cringe and say) "Yow! It's still hot!" Perform the fanning motion (crimp change) while blowing on it some more to 'cool it down' then hand out the coin, or put it on the table to allow them to 'go for it' whenever they wish.
I guess my main point is to have a motivation for whatever you do, while at the same time try not to be boxed in to only doing it "the easy way", or only having one way to do it.
I agree with Chicken that a shuttle pass, or a Bobo switch is probably the quickest to learn and gets the job done, but be sure to provide proper motivation for the movement. Don't just "shuttle pass" from one hand to the other then hand the coin out. If your lighter is on the table to your left and the coin is in your left hand, transfer it to the right hand (shuttle pass) so that your left is free to pickup the lighter and put it in your left pocket (ditch), then as an afterthought hand the coin to them for examination, or just sit it on the table and wait.
Probably the best advise is to play, have fun and train hard!
-ThisOneGoesTo11