Aha! Ok, now it makes sense. I couldn't see any photos where that part was included, but then I found the complete writeup which mentions that:
Real Guns - Making A Good Hunting Rifle Even Better - Jewell Trigger
Definitely just personal preference on my part. But upon looking I'm just surprised I can't find any for the Remington 700. I can find aftermarket high-end sears for my CZ 452. Seems odd.
Evidently I'm using the wrong term for the part. I believe it is officially called the "sear safety cam".
I don't think it is included with a Jewell trigger.
Maybe sear isn't the correct term for this part, although I saw in called that in the article which showed this photo. The part I'm talking about is the one above the small spring in the upper right of the photo:
This mystified me after I took apart my Remington 700 Milspec 5R and saw the cheap-looking MIM factory sear. Why doesn't anyone make a nice machined replacement sear? It seems odd that there don't seem to be any available for a rifle as common as the Remington 700.