I learned how to use the Ho 229 in full uptiers, but it’s a steep learning curve.
I’d suggest the Attacker, as it has decent climb, and strong turn with flaps. You still need to learn how to reverse people and get them to turn with you.
You are guaranteed a high ratio of downtiers in the Yak-15P, A21R, Strikemaster, He 162.
The F-84G and La-200 can take the fight in uptiers (unless you have to fight an entire horde alone).
Like what RXdima said, probably the Yak-15’s; you just have to stomach the low ammo. They’re decently maneuverable and good enough (Haven’t played them btw just anecdotal experience from fighting them.)
sea meteor maybe. it has later derwent jet engines which are often more of a drawback than benefit. but it does mean you have the climb to pick and choose targets whenever
It seems to climb at 30 m/s, around 500 KMH IAS. Do not use flaps over 700 KMH IAS.
Encourage people to engage you at 700 KMH IAS or less (if they are staying faster than you, keep minimally dodging until they risk to get closer and slower). While dodging, if you are sure you are inside their best potential turn circle (meaning their circle cannot intersect with yours), don’t turn as hard to conserve energy, while they bleed theirs pulling hard after you.
Use Takeoff flaps for a nice boost to turn when needed, or Landing flaps if you have enough energy over an enemy and need to slow down (or survive an attack). You have the tightest turn circle with landing flaps deployed. Make sure you lose energy when it is safe to do so (no 3rd parties).
If you use air brakes, deploy landing flaps too, it’ll magically add to the braking effect.
The other flap settings are also useful as you get more familiar with your energy requirements.
It all really boils down to “Unbreakable landing flaps below 700 KMH IAS makes funni turn”