Jonas–
I’m sure people do both.
If you are doing mobility pre workout have it focus on the skills you are performing during the wod.
It is good to have a couple things that you are working to improve and this may change every couple days, every day depending on the degree it needs to change.

You may have a check list of problem areas, but also go after tissues you are not keeping an eye on.
Very beneficial to freestyle and hunt for things. Hit tissues that are asymptomatic and keeps it in the loop.
Up regulate proprioception of the tissues and understand where things are at.
Kelly discusses this on the Daily Rx August 7th and an episode where Carl Paoli talks about freestyling to find things.
Episode 334: Informed Freestyling Always