Every time I look at this, the value proposition makes no sense to me. The DIY V1 and V2 only have instructions for adding a single HDMI input port (??), and the V3 and V4 are like $350 CAD, which is way more expensive than buying a used KVM on eBay. What am I missing?
I haven’t tried it personally, but Mox looks like a nice modern mailserver. It might do what you want.