Got it. Missed the part about it just being a flat.
I cook packers both LnS and HnF (and I guess MnM). I like doing LnS when I am aiming for a mid-day time to eat, that way, I can just set it up at night and let it cook all night while I get a full night's sleep instead of having to get up at oh-dark-thirty to start cooking. OTOH, if I am cooking for evening time, I like to go HnF.
You have WAAAAAAAAY more experience than me in the world of BBQ (like 15x more experience and your posts were the reason I started trying HnF, BTW). So I defer to you. But I have had success (at least with packers) at either end of the spectrum. The last time I did a flat, I think was over a year ago, and I injected with beef broth and cooked at 250 and it turned out great (although the bark wasn't that great). I was never able to get my cooker down to 225 (I hadn't mastered it yet) so I guess I really don't know how a flat would turn out at 225.
22" OTG; 22" Performer; mini-WSM; Brinkmann gasser; UDS (on the way); Maverick ET-732