Zen6c clocking above 4GHz would be a surprise IMO. AMD already ships Zen5c on 3nm in servers via Turin-Dense (
EPYC 9965 and so on).
Clock rates there are:
Max. Boost Clock Up to 3.7 GHz
All Core Boost Speed 3.35 GHz
Base Clock 2.25 GHz
Expect something like that for Zen6c too, with maybe a small uplift to account for process refinements in N3P.
The handheld is probably going to clock even lower. If it's a 15W TDP chip you can maybe afford 0.5-1W per core? Expect something like 2.x GHz on the handheld for a default configuration (which maxes out GPU performance), maybe with modes that clock down the GPU to get better CPU performance as some optional thing a developer can chose to run for their game.