On my FP3’s stock ROM, I liked the stock Camera app (a SnapDragonCamera offspring as I learned later) for its very effective realtime EIS in video recording.
I haven’t tried running the stock FP3 camera on /e/ like you, but I have found that /e/'s stock camera (OpenCamera) does not noticably stabilize the video. Neither on an FP3 (/e/ on Android 9 base) nor on an FP3+ (/e/ on Android 10 base). Even though on the FP3+ OpenCamera gives the option to turn on stabilization in video settings. Doesn’t make a noticable difference. Quite disappointed, actually. I’ll try some recent Google camera app mods next.
I’ve tried NGCam_7.4.104-v1.2 now on both phones. Didn’t provide noticeable image stabilization. Has anyone actually got image stabilization to work on any version of /e/ on a Fairphone?!