I'll be honest, that still makes me a little uncomfortable. Sure, if I'm precise enough the chances of directly copying someone are lower, but it was still trained on stolen art and may still have elements of that unwilling artist that I can't pick up on. I'd rather go into it knowing that it was trained on art that they got permission to use first.
The only results I can find for fully artist-approved training is the new Adobe Firefly stuff, but I'm not sure how good that is because it's still pretty new and just uses Adobe stock images.