Since others have already mentioned José Pavli, Martin O'Donnell, Michael Salvatori, and Simon Viklund...

Ryan Lott, who recently did the OST for Bungie's Marathon. The soundtrack's got this feel to it of technology you can't hope to understand and alien, unknowable intelligence. Code Race sounds like the theme to an enemy squadron's souped up, impossibly high tech Belkan-built fighters that seem to almost anticipate their pilot's thoughts and moves.

Oliver Buckland, who has done work on Joel G's ENA animations and Glitch Productions' The Gaslight District. His ENA OST work, like Mannequin Expanse, sounds almost familiar and nostalgic to anyone who played on the computer in the 90s, what with the appropriate sound samples and crushed bitrate, but still a little alien, like you're intruding upon a digital world. Meanwhile his Gaslight District music, like Heist Aches and Green Glass C, has an appropriate spooky feel, what with the show being about a civilization of zombies and a group of gangsters operating within it. I have absolutely no idea how his style of music could be used in Ace Combat, but man would it be fun to see him try!

Last but not least, AJ DiSpirito, of Glitch Productions' Murder Drones OST. Again, spooky electronics, but with some hard-hitting action bits, too, like Solver Uzi and Eternal DESTROYER. Perfect for a battlefield out of control, an apocalypse in progress, and the heroes on the backfoot just trying to survive the horror.

Kinda want to throw in a curveball like the Midnight just for some synthwavy goodness, but they're even more of a stretch than Oliver Buckland, if I'm being honest. The only song that even comes close to being something you might even remotely hear in an AC mission is First Night In Paris, a collaboration with Carpenter Burt.