I always find "challenge" a fun one to quantify.
I know
strong cavers who tend to find spiders or bugs their weak point.
Cavers who love heights but hates ducks.
Cavers who hate heights but love squeezes.
Cavers who love water but won't climb.
Cavers who love SRT but struggle with unroped traverses. etc etc.
What kind of caving do you actually want to do? I started writing a list of the most unappealing pieces of cave I know, and if you want test pieces - that's chill - there's plenty available, and plenty that will hand you your arse back (potentially with DCRO's intervention).
But if you're looking for trips you regard as fun - what are the trips you personally are finding fun at the moment? What bits do you like/dislike/find challenging?
In the event you don't get round to replying, go do Sidetrack and let us know what you thought of it.

[p.s. before someone kicks off, it's not remotely the most challenging cave in the peak district, but OP might enjoy it]