Please don’t, actually. But do update your Shimano Di2 shifters’ software to prevent a new radio-based form of cycling sabotage.

In current Shimano Di2 systems for Dura-Ace and Ultegra, there are two buttons on each shifter, both of which sit behind the brake lever. These buttons can be configured in a variety of ways.

So, for me, this eliminates the GRX 2X mechanical spec. That leaves 1X mechanical, which is just the right shifter, or 2X Di2, whereby you’d program it for synchronous shifting.