This great article and the other recent one from him started me down the path of thinking about an end-to-end optimized modern computer and operating environment.
If you _could_ (not saying it's easy or even necessarily practical at all) drop replace all of the slow stuff like high-latency keyboards, syscalls, CPU-GPU communication (i.e. effective HSA) and build some proof-of-concept operating environment (that was explicitly incompatible with existing stuff).. I think you could get a pretty fast computer. It would be fun to try.
Anyway is there a Cherry MX keyboard that has low travel and low latency overall?