0004.10 Inner Vertical GPU Mount with SSDs - Detail
Here's a closer look at the inner GPU mount with the SSD trays. It's tight and unlikely that you'd be able to squeeze in the cables for the trays on the left and in the middle. With the tray on the right, you should have clearance to actually mount an SSD in there if you want.
I'm not sure that I'd suggest doing that - that SSD will be getting heat from the GPU - but it's an option.
I'd recommend using this innermost mount only if you have a 3-slot GPU.