I can’t see how it would be any different from using a small amount of oil to cook the chicken.
No the fat does not permeate. It renders out of the skin and comes into contact with the thigh just like cooking oil would.
The only time I would probably take it into account is if you don’t use oil while cooking in which I don’t know how you would account for it perfectly.
It doesn’t make a big difference if you remove the skin before cooking or after. Bone-in, skin on poultry cuts technically don’t get processed as much as the skinless variety (i.e. boneless skinless chicken breast will have no visible fat attached but a bone-in, skin-on you would see some fat). But from a nutritional perspective it’s probably negligible since some fat would’ve drained in the cooking process. Same thinking for the question of if fat will permeate the meat it’s probably not much.
The fat from the skin absolutely goes into the meat during cooking. But how much? Probably not a whole lot. The bone in part is the kicker. Especially if you use a slow cooker you are getting more nutrient rich food from the bones and it just tastes better!Try making chicken fricassee’ with skin on bone in thighs vs boneless skinless thighs. Night and day difference.And, facts here- if it doesnt taste good you will not continue to eat it so just figure out the macros as close as you can and rock on!