@mitu
Thank you for this tip!
The boot is faster disabling "wait for network"
and I don't have this text between splashscreen and emulation station.
So, for anybody having buggy bluetooth with 2 PS3 controllers
with a Raspberry Pi 3B+ and Retropie,
here is a solution:
https://retropie.org.uk/forum/topic/19734/enable-disable-wifi-with-rfkill
Thanks again everyone,
we are going to have fun with my friends! :D