You can see the guide of Physical RK created by Crosccy. There's options not only Lindy for Crush Strike. Hurricane Fury, Robot Arm, Violet Fear with Golem card or MBTA with Ressless Dead card will do too. And use +9 Battle Surcoat for DA CS.
Others gear just like others Critical Build.
I personally like clearing mob on ET using Skill which doesnt need spesific target like Gene's CC. I prefer using DB RK/Sorc/WL. Using Gene need extra effort to move and "to target" the mobs. Meanwhile others just spam it on the ground.
Summary, with lot of buff gears from OCP for RK nowadays. Able for RK to finish ET faster.
Did ET duo last night, Full DB RK ft Crit RK. It was fast runs.
For hybrid? Gear Swap System is your friend.
What is budget build for Hybrid RK? I don't own ORC or Lindy Hop and feel like its too much to invest to finish ET when I can just gear a gene to get the job done.