Having just done the kitchen sink job I can brandish my experience....

The supplied instructions are clear; hand tighten only the *O* ring
sealed male tail. There is also a 70deg.C limit on hot water and 65
preferred.

The other end on mine is a flat washer sealed female tap connector. When
I tried to tighten this to the supply pipe, I found the coupler rotated
and twisted the flexible pipe.

Mindful of the recent thread about life/damage I slackened off the olive
clamp and allowed that to rotate instead.
--
Tim Lamb