Upper case letters are no problem for me, actually i was in the 8 grade or so before i stopped using that myself, and only as i found writing small letters was faster. ( this was of course in the paper days in the 70ties ) and the only school work they got out of me was what i had time to do in school, home work i almost never did, and surely not in the older classes at the end of the 10 year long nightmare.
Regarding the barrel tuners, they dont seem to have caught on, i have seen people reviewing them / using them / praising them, but the thing disappeared from their barrels anyway.
My feeling is a airgun was made properly, there would be no need for a tuner, at least for the great majority of shooters.