I think that the 22 gr difference would roughly be 5 fps.
Interesting,
I just ran a few number through Jackson website to look at FOC differences based on a 420 grain arrow (total), 29 inches length75 grain tip. 15 grain for fletches, 10 grains arrow wraps (enteredas nock adapter), insert weight 15 grains.
With a regular 8 grain nock, FOC is 6.3% (420 arrow weight)
With the lumenock, FOC is 3.6% (442 arrow weight)
Just general info. Even with heavier tips, the FOC will change a few %. Could be enough to through off a fixed bladed broadhead tuned bow and possible POI.