If you have any additional specific on the type of rings used and factory gap specifications I'd like to hear it. Obviously the Hellcat's 6.2 vs the 6.4 provides an advantage in piston design for FI. But the Hellcat setup produces 11.6psi of boost, almost double what a basic Whipple kit is likely to make.
The Hellcat has a 9.5:1 cr, vs 10.9 in the SRT 6.4 and 10:1 in the Ram. So again, considering the relatively mild boost levels I don't think the 10:1 is unreasonable at all. Arrington offers a kit for the 5.7/6.4 Hemi (cars) and they state it's safe at 6psi on a stock 10.9:1 CR motor with hyperutectic pistons. All the Mustang 5.0 kits run just fine under 600hp with a bone stock motor, and they run 11:1 CR. Point being, compression alone isn't necessarily an issue.
Arrington Performance HEMI 6LB Supercharger Kit - shopHEMI.com