Do I use bone-in, skin-on thighs for chicken thights roasted in paper bag?

Many thanks!!

And old wise saying is "the closer the bone, the closer the flavor" (or something like that).
The bone gives of flavor as does the skin.
Can anyone, including health guru's, resist some crispy skin - chicken or turkey, or pork crackling! No.

For the most flavor, yes. You can use boneless if that is what you have available or if that is your preference.