Your the one eating it, how fatty do you want it?
What was the fat content of the 30% pork that went into the mince?
If it was back fat then you're probably fine. If it was belly I'd bump up the fat a bit, if it was lean'ish pork then I'd add a heap of extra fat.
The speck through a 10+mm plate would be fine IMO but large cubes won't help the rest of the mince much.
Just look at the total fat and meat and aim for 30%. If it turns out a bit to rich or lean for your taste you'll know which direction to go next time
Try to get that core temp right too. If it climbs too high it'll over cook and be oily and dry at the same time like a bad meatloaf.