Can you elaborate more about the tradeoffs here?

I'm in the same boat, looking for as light as possible with a much battery as possible, was banking on the 16 yet we get 9 hours instead of (an assumed) ~10-11, and 2.1/2.4kg.

Somehow the Thinkpad Extreme X1 and the new Zephyrus G16 have similar CPUs, dGPUs, a >90Whr battery and they weigh less than 2kg.

Where's most the weight going? Will I be able to buy a FW 16 and eliminate weight to achieve similar specs? Literally asking about using a "stripped down version".