If we had the option of substituting non-xxx clips for the xxx ones, I'd use it.
That would be an almost pointless option. Totem would still have to make the clips that you do not want so as far as they are concerned it would either be equivalent to making a significantly longer show. or to continuing to make the shows with their current lengths but only giving us part of the show for the same price as we currently pay, or to reduce their profits if they sell partial shows at a lower price.
A function I'd like to have is partial playback of a xxx clip.
The clip would end once the rating exceeded the specified rating in the settings.
Many of us like the long clips that give us a full striptease. Splitting these whenever there is a change of eroticism level would be irritating for us that like these and also would entail extra QA work being expended for each card.
I simply use the menu option to skip to the next model or next costume when I feel that a clip has gone to far for my current mood. I wish that there was a next clip option (or next sequence of clips from the same card) as well. Both would seem to be possible to add to the player without any extra data about the clips needing to be added.