Crimson bio tech didn't help his future self, so I doubt it'd help his current self either. And I can't imagine him not knowing the secret to the sun saint and ageless swordsman's 'immortality', so I doubt those methods are useful either.
And it's not as good as you're thinking it is. Sure, his body will reach its prime faster, but he'll be sacrifing his chance improve his techniques even further while his body is still developing. Rather than aging, I think it's a better alternative for him to train under the ageless swordsman. Since most of his techniques came from future Ruoxi, who was ageless swordsman's student, I'm sure he could learn a thing or two from him as well. Of course, since Ragna isn't particularly talented, it'd likely take a few years to see any results, but it's still preferable to just aging faster.
Another concern that I have is at what rate he is aging. If it's just a 1 to 10 ratio then that's okay, but if it's a 1 to 100 ratio or more then that means he'd age 8+ years in just a month, making his lifespan less than a year. Maybe the carla clone in charge of him can help him in this regard? Last time I checked, she was developing her own personality, just like the now deceased wing monarch. Maybe her abilities will slowly change as well, making her capable of getting past Ragna's silver resistance and slowing down his aging?