Not even sure why you guys are arguing. All of this can boil down to:

• More RAM is beneficial, especially when it's shared by the CPU and GPU.
• The biggest bottleneck for most games on the Steam Deck is probably not RAM/VRAM, though.
• Faster memory will probably improve performance more than more memory.
• All of this is entirely dependent on the game or application you're running.

But the biggest point should be:

• Good fucking luck desoldering and soldering BGA memory chips by hand.