it is most definitely something I include. While the note may not look quite like what you wrote, it would be more of an "incomplete" grade for an infielder whom I've only seen wear a mask in games. There are several things I'm looking for an infielder to do consistently, then a few more I'd look at once those things are established in my mind. The mask takes away my ability to see some of the things that I need to see the girl doing consistently before I'd move her on to the next phase.
Again, it isn't about the reason she's wearing the mask. It is solely about my ability to evaluate her completely and to apply the same criteria to her as I do to other girls before moving them on in the process. I am a former infielder and I am a huge stickler for head position and eyes when I am both teaching infield and when I'm scouting prospects because I believe about 80-90% of all fielding errors occur due to someone turning their head too soon, moving it "out of the way" on a tricky hop or someone averting their eyes (usually to find the runner or their throwing target) an instant before they have the ball. I want these things to be 100% ingrained and natural for the girl and I simply cannot grade any of those things honestly if a girl is wearing a mask.
You make some valid points, and I will not disagree with much of this. And to be honest, it is a concern of mine when/if my DD ever decides to remove the mask. Once that time comes, one of the first things I will look for is her "comfort level" (for lack of a better term) when fielding. I played strictly at 3b my entire little league, teener league, high shool, legion ball, and fastpitch softball career, so I too stress many of the things that you stress. However, it seems that much of your argument is based on the assumption that the player will either choose to stop wearing the mask or forget to bring it to a game. Provided she has the mask and is wearing it, couldn't you assume reasonably that her skill level will remain the same?
Likewise, do you make similar notes concerning hitters that wear elbow guards, ankle guards, face masks on their helmets, etc. when hitting? These items are also produced as safety devices, but it is my belief that the hitter gains a sense of confidence when wearing them. If a hitter forgets to bring her elbow guard to a game, will she be as aggressive when hitting an inside pitch? Will she be as likely to allow a tight pitch to hit her. Or will there be a sense of doubt in her mind that "it's gonna hurt!!"? All high schools in my local area still utilize batting helmets with face masks, but many of the colleges do not. Will that have any effect on the hitter's confidence at the plate? Do you make similar notes about knee braces or ankle braces? If someone is healing from an ACL injury (as an example), not only does the brace provide support to the injured area, but it also gives the player a sense of insurance that the knee will not blow out again. Is she decides to take that knee brace off, will she be as confident of a player? I guess I am having trouble understanding how a fielding mask is any more or less telling of a player's ability than any of these other items...