I agree with several of the folks above who said to just build the case for us and then let us buy the backplane options we want in the store. Why? Because the storage industry is actively transitioning to EDSFF and yet, the majority of us will still want to run SATA, U.2, etc. for many years. Thus given all of the industry churn in terms of storage form factors, the most important thing that the Homelabs Team can give us right now is storage form factor “Flexibility.” Pure and simple.
And I think the way to do that (which was not offered in the original voting) would be to make the backplanes fully modular. How would that work in this case for say a Q30? Ok, well, a standard Q30 has 2 backplanes with 15x drives each. So break each row of 15x drives into 3x modularly connected, backplane plates. And then allow us to swap in and out whatever 3x plates we want per row.
Backplane Plates could be:
- SATA (simple plain jane SATA or SATA / SAS, whatever keep the costs as low as possible)
- Tri-Mode (SAS, SATA, NMVe)
- EDSFF (there are multiple form factors here, EDSFF is not 1 single size)
- Blanks (if we wanted to run long GPUs)
The benefit of this idea is that everyone wins. If you want to go cheap, great. If you want to go hardcore mode, you will pay more, but great. Yes, my idea takes more work upfront from 45 Homelabs / Protocase, but this way everyone gets what they want. And Homelabs sells way more units since the installed base for this product, by design, will be much wider than the ideas listed in the original voting above, because this case isn’t going to be solely dependent on selling into 1 single part of the market (a low costs at all costs enthusiast vs. a moderate needs user vs. someone with very high end needs). This case could instead bridge all use cases for this product.
TLDR… it’s time that 45 Homelabs gave us “LEGOs” for Backplanes 
Because again, as I’ve said in other posts, I’ve looked at a lot of rackmount server cases and IMHO, the quality of the Backplane was the most standout piece of the HL15 server case. It’s the feature that other Server Case manufacturers have yet to fully replicate. So I would love to see the larger 45 Homelabs / Protocase team take that lead, and then really build on it to get this next gen case up to an 11 out of 10 reviewed kind of a case.