As BGS' website explains, the highest 'ordinary' grade available is the BGS 10 Gold Label, where one of the firm's four grading categories (surface, edges, corners, and centering) is allowed to score a 9.5 without bringing down the overall score
You typically want to save Veto for powerful card advantage spells like Treasure Cruise, Pieces of the Puzzle, Light Up the Stage, Storm the Festival, and most Planeswalkers
This time, its her normal U rarity Supporter card, but in the Master Ball Mirror variant
Most Auras decks are looking to be as fast and efficient as powerful, and paying three to tutor an Aura and then giving up a turn of attacking to flip it probably isn't worthwhile
Speaking of Palinchron, its also very easy for a mono-blue deck to find ways to go infinite with its mana, which can translate to infinite blink effects, card draw, tapping down all your opponents creatures with Thassa, and other extremely convenient side benefits that can set you up to win the game