The darker patches are better.
By printing tons of actual negatives with actual images on film. It’s a time-consuming thing. That said, your conversion to Pro ink and the driver will help (basically it will eliminate and introduced micro-banding that came from QTR in the past and this printer model in the present). I really do suggest you apply for the driver. I already gave you the link in previous posts but here it is again: Piezography Driver - Piezography
The reason why I require application is so that I get your contact info and so that you read the page and requirements of being a beta tester.