I'm late to the party on this one, but I've been detailing in SU since version 2 (20 years ago!) and layout since it's first iteration (which was tedious). I've found that I tend to go down a dual route, depending on what level of competence I have in the contractor and/or the complexity of the build.
I Scrapbook most of my standard details which are small SU files in the same folder as the Sketchbooks. This makes a lot of them nicely lightweight in LayOut too, and if there's a change in legislation I change the Scrapbook file accordingly.