I would like to help with my first time suggestions as well (S3 XL order 3/5/17, assembled a few weeks ago). I agree that the "official" assembly instructions are somewhat lacking with regard to the XL model, with my newbie issues being:
- Homing switch mounting details
- Wire harness lengths and routing
- Installation of dragchains (Y-axis -> appropriate removal of links and location for attachment)
- Axis definition (Y_left = Y1, Y_right_Y2)
- GRBL "stock" settings were nonsense out of the box, needed to revert to default settings to run "Hello World"
I don't know if there is any need for additional photos/text or just general editing.
Is the best way to contribute to become an editor on the Wiki page or should I be private messaging a guru like @WillAdams directly?