Hey there, fellow Game Day champion - and congratulations. :)
I'm a little taken aback by your analysis that Mono Red Aggro was an especially easy matchup for you, given you're three colours to his one and how explosive the deck really can be.
Other than that, interesting to hear about your meta.
I myself won game day with a version of Jeskai Tokens. I was the 8th player in top8, having lost a tight mirror match round 1 against a more controlling sideboard variant. I got my revenge in the semifinals by sideboarding unpredictably.
Short breakdown of matches:
Round 1 - Jeskai Tokens mirror - 1-2 Loss.
Winning the diceroll meant a lot in the matchup. My opponent slammed Ascendancy on the play and despite being able to mirror her plays and generate boardstate, she was always one turn ahead. Game two was a Negate-fight over my Glare of Herecy targeting her Ascendancy. which ended in my favor. Game three was decided by her finding a Treasure Cruise first.
Round 2 - UG Control - 2-1 Win
I lost the first game against this surprising kitchen-brew that played Hornet's Nest into Kiora and accelerrated into Stormtide Leviathan, which I couldn't find answers to. Boarding in fliers and more removal, I easily took down games 2 and 3.
Round 3 - WB warriors - 2-0 Win
My opponent was playing his second standard tournament and wasn't familiar with a lot of the cards. He didn't manage to draw very quick starts and I was able to out-value him and surprise him with big prowess monks.
Round 4 - Mono Red Aggro
The cold sweat matchup. My opponent kept a one lander and stayed on one land for 4 draw steps. The one drops were a bit scarce too, so I managed to stabilize and bleed out a victory. Game two he got two lands immediately and spit out quite the board. I drew my single Jeskai Charm that gave lifelink to Mantis Rider, which was doing double-duty against Mono Red's attackers thanks to vigilance. Despite gaining 8 life over the match, I was down to 2 when I finally stabilized with equal amount of creatures and 4 mana open with a negate and lightning strike in hand. The match felt like a steal, with me opening with good hands and the opponent not so much. He was no rookie to RDW either.
Top8 - Round 5 - Mono Red, but no aggro - 2-0 Win
My opponent did nothing but slam lands for the first three turns, and I was beginning to sigh in relief after immediately answering a Rabblemaster with Lighning Strike, only to be surprised by a Stormbreath Dragon. Luckily I had kept a hand with Stoke the Flames (which I had thought unoptimal while it seemed like another mono red matchup) but turns out it was perfect against Stormbreath. My opponent's draw was a one trick pony, and Stormbreath had been it. If I hadn't immediately answered it, he would've won with his Temur Battlerage and Titan's Strenght. Game two went down much the same way, using Ascendancy and Mantis Rider to cast a second Mantis Rider and Stoke in the same turn with only five lands in play.
Top 8 - Round 6 - Jeskai Tokens - 2-1 Win
Revenge time! She had a better ranking and decided to go first, but I managed to steal game one by this time finding Cruise first and forcing my opponent to 2-1 themselves to simply trade Mentor for Mentor. Game two I didn't find an Ascendancy, nor a chance to play it when my opponent curved out perfectly. By game three it was clear she had sideboarded into more "inevitability" and control. Being the "Beatdown" I even boarded out some of my Mentors and Ascendancies to make room for aggro cards. She didn't expect Stormbreath Dragon. She didn't expect Goblin Rabblemaster post-Anger, and she had boarded out some of the lightning strikes only to find me siding in Mantis Riders.
Finals - WB Warriors - 2-0 Win.
An impressive aggro deck had made short work of control decks that I managed to not even face in the tournament. Curving out to Brutal Hordechiefs, he managed to assault me down to 1 life, but by some miracle (known as double Ascendancy in play) I alpha struck him from 20 to 0 the following turn out of the blue.
The final match he mulliganed to 6 and even that keep was sketchy judging by his body language. Perhaps the easiest game of the tournament, I always had an answer in hand to his individual threats until my value-engine overperformed him getting nothing but one draw step.
In conclusion I love Jeskai in general because of how many strategies are open to it. It is entirely possible for me to start with Tokens and sideboard towards aggro control or aggro both. You could even tailor your sideboard to be midrange if you wish.
MVP card of the tournament for me was Mantis Rider, due to how unexpected it was to many players. It's both a fast threat against control and a double-duty blocker against aggro.