Hold it, there. I've not insulted anyone yet, real or imagined.

But, I am watching the TdF. The panel addressed the larger pulleys and said "half a watt."
Now, those Ceramic Speed pulleys are selling for $600.

Other versions are as low as $60. Or the price of a nice used Ultegra or Centaur long-cage RD.

There are also the carbon and Ti custom cages coupled with the oversize ceramic-bearing, double-stitched for extra cushioning, kung-fu grip pulleys, and from what I understand, the bike freakin' rides itself.

I'm actually thinking about selling one bike and then putting all that money into aftermarket gadgets on another bike, just to see.

I did pick up on the long-cage = smoother, short cage=quicker opinion.
I kind of agree, but I'm not sure if I'm expecting it and being confirmed or it's accidentally getting my attention and I just rationalize it.
I just know that few things shift quicker than a 1-cog jump on a Dura Ace short cage 11-sp setup.
It's just more fun with a 9-sp because it's shiny AND old and there's something to that cable routing, I swear it.

I'll experiment with an SRAM Red short-cage 10 vs an SRAM X9 clutched medium-cage.
My guess is the Red with a Roadlink will be quicker. And a lot lighter.