Spin & Go tournaments on PokerStars are 3-player, short-stacked, hyper-turbo tournaments. Because all players are short-stacked, most of the decision making happens preflop. Because they are hyper-turbo and 3-max, you need to be aggressive. As there are only 3 players you’ve got plenty of room to display plenty of HUD statistics. I’d recommend these stats:
Blind Steal, Fold to Blind Steal (effectively, the button has a blind steal opportunity on every single hand!) You could just load up your HUD with every possible blind steal stat (fold to blind steal, raise blind steal, call blind steal, blind steal from button, blind steal from small blind) and you’ll already have a ton of information that would converge to accuracy quite quickly.
Three-bet and fold to three-bet. I wouldn’t care too much about four-bet stats, because a four-bet is going to be an all-in raise most times.
Postflop, I’d use continuation bet, and fold to continuation bet. “Donk Bet Out of Position” and “Fold to Donk Bet Out of Position” could be useful for distinguishing between donks and maniacs. Donks would have a high Donk Bet Out of Position stats.
Simple, but effective I think. You can add continuation bet by street, but I don’t think Spin & Go’s offer the opportunity to use such detailed stats effectively.
Here’s what it looks like in Poker Copilot 6’s HUD Layouts window: