I feel like a lot of people have the impression that HRP runs contrary to the whole point of playing CM, that is, being a unga dunga space marine killing xenos.
Yet, I think that one of the best ways to enjoy the game is to both engage with other players at any opportunity WHILE doing the usual unga shit. Any role, particularly support roles, can benefit from this.
I dislike using the term HRP because it implies there's a classification, or "levels" to what constitutes RP. So long as people are having fun and trying just a little bit getting into character, it's RP. You don't need drawn-out dossiers or funny accents for that, just a certain amount of earnest engagement with other players. It's something akin to improvisational theatre: engage with your improv partner, build off what they throw at you, and be uninhibited.
I absolutely guarantee no one is going to look down on a player for trying to RP, even if it's not the most engaging, or funny, or interesting attempt at it. Being concise, honest, cooperative, and having initiative puts you miles above most other players.
Forcing people into HRP won't work. All you need is patience, and be willing to listen, and just a little bit of creativity. If won't always pan out, but when it does, I guarantee you'll have some of the best times to be had in this game.