This might not help everyone, but it did help me.
With both this flight, and the first one, my PC performance was absolutely atrocious. I’m running a i7-7700K with a GTX 1080 and while GPU never seemed to be a big issue, the CPU always has been, shooting right up to 100% usage from the moment I start the game, causing insanely bad performance while playing (or with the computer just trying to do other tasks in general).
Solution that worked for me:
After launching the game, find the HaloInfinite.exe process in Task Manager (under Details tab). Right-click it and select ‘Set affinity’ and uncheck some of the CPU’s from the list. My CPU is a quad with multithreading so it shows CPU 0-7 for me. I uncheck the bottom 3. Experiment with this on your own. If I removed to many the game itself starts chugging due to not enough power.
Freeing up the other threads allows the computer more stability and Infinite doesn’t REALLY need all that power anyway to function.
After I’ve done that, I’m enjoying the game currently at 1440p @ 70fps with minimal stuttering. This is clearly something 343 still need to look at, but this workaround works for me every time I launch the game.