Additionally, Joule Creep is normally more prevalent in GBB guns because of the physics in expanding gasses rather than compression.
HOWEVER. you CAN create Joule Creep conditions in an AEG
For example my g36 has a 407mm barrel with a end ported cylinder. It's configured currently with a modify 120 spring that is shooting 380fps with a .2.
Using an FPS calculator to work out 380fps with a .2 I get 1.33J
If I work backwards from that math 1.33J with a .32 is 299.9 FPS.
The gun chronos between 305 to 310 with a .32 which is 1.42
I futz with V2s, V3s and V6s. I could be wrong... but probably, most likely not, as far as I know.