I've heard it's actually beneficial for your ankles long term to get some tilt/pan on them. It reduces your chances of injury by strengthening the twitch muscles in your ankle and legs.

Important to note the point is "trail running" not "alpine running", gravel and dirt vs, steep inclines and big rocks.

Anecdotally, just adjust your pace/length until you're comfortable. I've always done mixed asphalt/dirt-trail and there is a notable difference in my knee fatigue when there is a bigger ratio of one or the other, would always prefer a nice gravel or dirt over the road.