I would carry on with what you’re currently doing, it’s clearly working! If you’re already pretty lean and muscular then further weight loss (if any - this might already be your optimal weight for gravel racing) should be quite incremental.
I wouldn’t think about trying to lose another 5+ kg. I would think about carrying on with good sleep habits, fuelling your workouts well, and your body will find it’s natural weight in response to that training stimulus. I see a lot of lean muscular people come into cycling who gradually shed some of the muscle mass over a couple of years as their body responds to doing lots of endurance training. If you really do feel you can lose weight and still be healthy and nailing your workouts, then with the time frame you’re talking about you can target small deficits e.g. Losing 1kg a month (or 0.5lb/week) is slow enough to give you time to dial back if you’re starting to see a negative impact on health or performance, but still plenty enough to get you in best shape for next season.