I initially hated the idea, but if it's possible to hit crazy benchmarks without trains then it gives a new way of reaching mega base.
Also it can limit the reliance on blueprints. There is something satisfying about pasting a big block, but it gets repetitive when you are pasting your 8th green circuit block.
I'm sincerely confused as to why you would want more than one keyboard. To me it sounds like owning more than one printer, but even less convenient. Can you explain it to me?