I'm genuinely confused by the graphic-representations I've seen of this bridge in use as to whether or not it will fit for what I want to use it for.
 
The bridge: https://www.evga.com/prod...aspx?pn=100-2W-0130-LR

 
The motherboard: https://www.gigabyte.com/...AORUS-MASTER-rev-10#kf

 
Based on what I'm seeing, it's 1 slot too long, isn't it?  Or am I mis-understanding what 4-slot means and it's 1-slot plug 2-3 4th-slot plug?
 
Looking at it now, I'm 99% sure it's the wrong size - RIP me being able to get a "free" NVLink bridge with eVGA Bucks to be able to have fun with SLi-ed 3090s for a few days.

It looks like it would put it at the M.2 space so no.

There is a whole thread about this, and members have found a few companies making 60mm bridges for Quadro A6000 cards, which as supposedly compatible with RTX 3090’s.

I am pretty sure most companies, to include NVidia, are mostly worried about the fact that the air coolers are mostly 3 slots, or close to it, on almost all RTX3090’s. Yes, water cooled cards are thinner, but the 3090’s get warm with great airflow, and many people refuse to run watercooling because “it’ll leak”, so they want to run two air cooled cards, which will kill the cards performance because the top card will overheat.