Disadvantages of an RC rig1) It doesn't give a core that can be studied. It gives a pile of rock chips and rock dust. If you don't care about the Jurassic, fine - grind through it. You want the Triassic core so you can study it intact. Grinding through the Triassic is an option of last resort.
2) RC is known for sample cross contamination, unlike cores. Once again if you don't care about the Jurassic, fine - grind through it. You don't want to cross contaminated your target rock.
These bullboards are full of Monday morning quarterbacks who don't even understand the game!