Have you tried with Boneless Chicken?

I only had 1lb boneless skinless thighs and about 1lb Dutch gold potatoes. Since my chicken was lacking bones & skin (and I didn't have as much potatoes), I was worried about the cook time & temp. I kept the same initial cook time (20 minutes at 425F) but then used the leeks as mostly as "cover" to keep the chicken from overcooking. I scattered the remainder throughout the pan to get some frizzled leeks.

I also popped a separate tray of asparagus into the oven (upper rack) when adding the leeks so I didn't need to reduce the oven temp. I kept the same cook time of 25 minutes at 425F.

If you're not planning to roast additional vegetables like I did, I'd recommend reducing the oven temp to 400F and keeping the same timing. This way the potatoes can still cook through and get crispy.

I agree with Nancy about the timing. I also read through the comments on the recipe, and a couple of people did use boneless chicken thighs successfully. I think pork would be fine, too, as long as you watch the timing.

Haven't made this one with boneless meat, but boneless chicken roasts faster than bone-in, so - ti prevent overcooked or dried out chicken - I would shorten the first roast for meat (say, 10 or 15 minutes instead of 20), & keep the second roast for potatoes at 20 minutes.
And start checking the meat by thermometer starting about 10 minutes before the end of the second roast.
Once it's reached desirable internal temp (about 165F, if memory serves), remove the chicken pieces, keep warm under foil at room temp, finish roasting the veg, combine all and serve.