BRR tested the slick and SS in TLC and Plus, but they also tested the Rene Herse which are similar... the difference stays consistent and will be consistent for the SK.
https://www.bicyclerollingresistance...&minknobe=-0.1
There's a significant rolling resistance / ride difference between the PLUS and regular TLC. The WTBs never test well in terms of RR, and roll like the Plus tires. The Plus have about 25% ( 26.6w vs 20.8w on the SS; 28.5w (inferred) vs 22.7 on the SK)
higher rolling resistance from the ~33% thicker rubber. That's per tire, so you're looking at about 2x those values, so if you're cranking out 200w, the regular tire would save you 12w or 6% of your power.
Maybe have a look at the Pirelli Gravel H (20.3w) in those sizes and save a few more watts. These would save 16w / 8% of your power output.
The SS is kind of useless in my view. For LA, you're looking at a layer of dry dust over smooth hardpack in most cases. You'll want mini-knobs to reach through the dust layer during braking and climbs and cornering knobs. The SK is the minimum you'll want to do that. TIres like the SS and g-one allaround just dont' have the knobs to deal with the dust layer. The Conti Terra Speed, Spec Pathfinder, and Pirelli H might work, but the cornering knobs are minimal. The