If I wanted a lightweight 338 I’d build a 338-06 or 338” WM.
While almost no actions handle the WSM’s as well, I have no love for the Kimber 8400 MT.
The 338 RCM is destined for the trash heap of history. For me, I can see no reason to go there, and I’d take the 300 WSM over the 338 RCM every day no matter the platform.