Where to use JKLS leftovers (CHS, ROLO, Lando)

Crancor food.

Depends on your GP range. In general, the answer is nowhere, they aren't good.

You can try Lando Lead Han Chewie in 3v3 gac, but just Wedge L is better.

Lando in theory can work as 5th in a Bando team, but not worth the mods IMO.

At lower D1 or D2, some people try CHS with scoundrels on Defence, but it isn't good usually.

ROLO is a hail mary if you need to hope to get the AoE to hit one toon 10 times.

But mostly they ride the bench along with Rose, FOTFP, and Krennic from GL requirements.