Next up: the drivetrain. I personally am a big fan of 1x. Primarily because it gives you one less thing to think about when riding. If you live in a hilly area or if you intend to go on bikepacking trips with your rig, I recommend using a double chainring. With a 31T small ring and a 36T big sprocket, you should be able to tackle even the most demanding climbs.
Then there's the question of mechanical or electronic shifting. I come from a bike touring background, so it took me a while to switch to Di2 because I was insistent on putting reliability and repairability above all else.
At first, I used Di2 to race and bikepack close to home, immediately loving how smooth and accurate it was. Gaining confidence, I took it on longer trips, until I finally decided to tour remote parts of Southeast Asia. For almost two years, it has performed so consistently despite the abuse I put it through.
I think deciding between mechanical or electronic shifting is a personal choice. My two cents: There isn't one that is more reliable than the other. They are both well-suited to day rides, races or bikepacking.
Flared handlebars are another anomaly on gravel bikes – this is where your drops are wider than the hoods. And these drops are also usually shallower than on road bike bars. Thanks to the wider stance, flared bars offer more control. The laws of physics are such that the further away your hands are from the stem, the more accurate your steering is. But I also feel that gravel-specific handlebars offer more comfort.