For like TRUE stealth it would most likely be the F-117. Any other modern stealth fighter is probably (and hopefully) far off in the future as almost all capabilities they have aren’t implemented game mechanics yet so it would be basically pointless before then.
What i personally think is more likely to come first is the addition of Electronic Warfare and thus also Stealth by radar jamming and fake target generation. This would be easier to implement as its basically one or two mechanics and then just add it to the planes that have it internally and design the EW-pods for those planes that carried/carries them.
Where did you get the 0.05-0.1m^2 from? This document shows Eurofighter has an rcs of 1.5m^2
Given that Flanker here has a radar range of 120km for a target with an RCS of 10, the Flanker would detect Eurofighter in look-up at 75km giving it an rcs of 1.5m^2. Reduced look-down is not modeled in-game so it is ignored.
We have more recent documents now which show the RCS of Eurofighter to be ≤1.0 m2 when carrying four AMRAAMs and two ASRAAMs.
That document is either referring to a eurofighter with more ordnance/external tanks. Or more likely simply dates from a time when there was more uncertainty about RCS / Radar performance.
Itll probably be the F117A as an event vehicle to test the stealth mechanic, although it wont be that usefull, and will be useless in air rb, it only carries 2 LGB’s internally and dosnt carry flares, so it wont be seen by radar, but if an IR missiles locks, your dead, its also not very fast
Someone claimed before on the forums it could have 2x Aim-9 (I didnt believe the source, but im also not familiar enough with the aircraft to dispute it either)
Wont be modeled. Harrier should be able to hide its exhaust and defeat any IR missile by just positioning the wing between the seeker and the exhaust:
Spoiler
But in game, good luck defeating any IR Missile with a dozen flares
That is an AIM-47 Falcon (the predecessor of the AIM-54 Phoenix) being loaded into a YF-12 interceptor not an SR-71 (the YF-12 was a prototype based on the A-12 Oxcart, which looks very similar to an SR-71 but is not the same).