The FFB really hasn't bothered me all too much in slow motion, usually because I have the wheel in my hand while it's happening. Recently however, during the ETK Driving School campaign, it got very annoying. Any time I'd finish a part of the campaign, the game entered slowmotion, and put my wheel into some very forceful FFB patterns. So much so that things were falling off my desk. I'm using the default FFB settings for the G27, and I'm sure I'm not the only one who has had this experience.
I agree, in the slow motion, my G29 was shaking everything around, and almost shook itself off the desk.
Please consider this as a feature. BeamNG is out of the question to play at night currently, as whenever slow motion happens, it's so violent that it wakes people up (default settings).