@nprofile1q... I'm gonna be honest I haven't had this problem because I've only ever used extremely thin paint for toning or I skip it altogether (digital artist brain, I like the contrast the blinding white background gives). I'd experiment on a tiny bit of canvas and check how hard you need to draw with graphite for it to show through the base tone layer. Alternatively you could just tone your canvas in bulk, let it dry for a few days and then draw over it with pencil later