Exhaust flappers

I am restoring a 75 Southwind 18. Putting a brand new engine in it and it’s coming along quite nicely. I will be posting some more pictures soon on my other thread.
I just spent an hour researching Exhaust flappers on the forum.
I’m trying to decide if I need them or not. From what I gather some folks think you do and some think you don’t.
Has anyone had any experience not using flappers on a mid 70s boat and had any problem?
I am sure it’s a good idea to use them and be safe, but I think it looks so much cooler without them.
I am using pleasurecraft marine center risers for Exhaust. These are much higher than the old log style that was on the boat when I got it.
Just thought I’d throw that in case someone wondered.

Thanks
I’ll give it a try

Good to hear from you, Ken.
Ultra conservative and worrying are not things that I participate in very often.
I’m more likely to have a good time and let somebody else worry about it.