Jerseys during Warm-ups

[BillyMac]

So a player can be charged with a technical foul for removing the jersey within the visual confines of the playing area, but there's no penalty for not wearing a jersey between the officials jurisdiction beginning and the beginning of the game? How about a player whom the official identifies as wearing an illegal undershirt, removing the jersey within the visual confines of the playing area to remove the illegal undershirt, and then putting his jersey back on before the game begins?