I think code "slow" development should be replaced with "foreplay" or "for women"

If I read porn story i am not interested in long descriptions how story protagonist is discussing his business plans.
Also i am not much interested in which how mater brings his slave to the expensive restaurant where he spends 2 chapters of story, then they go to buy some dress what again takes 2 chapters of detailed descriptions.

That kind of stuff is typically interesting for women but for men it is turn off.
It is not necessary bad thing, it just needs to find appropriate audience.

Another kind of "slow" could be slow progression from soft to extreme content.
we may have lots of action but it gradually gets more and more extreme
that should be correct use of this term.