Man, that's a pairing with some surprisingly distinct flavor. People often mistake them for another 'enemies to lovers' duo, but the appeal's way more specific. Rodger's chaotic energy crashing against Boxten's structured, almost rigid persona creates this friction that writers love to explore in predictable patterns. The 'Caregiver vs. Chaos Goblin' trope is huge—scenes where Boxten is trying to maintain some semblance of order while Rodger gleefully dismantles it, leading to that inevitable moment where Boxten's control slips and he either snaps or, more interestingly, gives in. There's also a ton of 'Forced Proximity' stuff, like them getting stuck in an elevator or having to share a room on a mission. It lets the tension simmer in a confined space.
What I find myself clicking on more often, though, are the quieter ones that flip the script. 'Competence Swap' fics where, against all odds, Rodger is the one who has the specialized knowledge to solve a problem, and a grudgingly impressed Boxten has to rely on him. Or 'Injury/Illness' fics where Rodger is the one hurt and Boxten's cold efficiency masks a panic he won't admit to. The trope of 'Boxten Secretly Likes the Chaos' is a winner, too—the idea that all his rules and protocols are a cage he built for himself, and Rodger, infuriatingly, is the only one with the key. Honestly, a lot of the best stories use these tropes as a skeleton but flesh them out with the little moments: Boxten remembering how Rodger takes his coffee, Rodger noticing when Boxten's 'professional' mask gets a tiny crack.