I think you're missing the point.
It's not about what I use. It's about what I'm subjected to, and have no control over.
It's about what other people use when they send messages to you. There is no way to stop their full screen effects, "bam," "wow," "kaplow," etc. from triggering on your device - period. There is no toggle.
Reminds me of the old Batman Series that used to play on television. UGH!
The only way to avoid it, is to not upgrade, since this updated messages app comes with the full FW update. Therefore, I will be staying on iOS 9. I don't consider 10 usable until they provide an option to block the effects and other junk they pushed into the Messages app on my end.
Too bad, there are some really great features in iOS 10 that I love. I won't be using the POW / BLAM like batman either, but the minor 1-2 times someone may use it to send me something is not enough (for me) to lose out on the great stuff in iOS 10. Plus I will be stuck, since I can't take the iPhone 7 coming in Friday and go backwards anyway. But if you're waiting for Apple to give you an on/off switch.. I personally think you'll be on an old iOS until the phone dies.