For best reverse sear results, I like to cook tri-tip up to 5 degrees less than my desired final internal temperature. Then I'll let that rest, uncovered, on a raised rack so the tri tip isn't resting on a flat counter or plate (doing it on a flat surface kind of steams the surface of the meat touching the plate, causing more juices to flow out).
For me, the key is letting the meat rest until the internal temperature stops rising. Then I'll put it back on to sear for just 1-2 minutes per side and the temp rise is negligible at that point.
I use an 8x8-inch stoneware pan for the same reason, keeping the peppers from falling over. I noticed that the bell peppers with 4 bumps on the bottom instead of 3 stand upright better but even those are uneven sometimes.