Well now that I've been running the drone a few times, getting out of a chair feels like activating the assisted takeoff. I will most definitely reach about 1 ft above the previous point assuming that altitude hold is still working.
And sitting back down in a chair I find the downward vision sensors see a circular object but not with the familiar H in the center.
Nor is this object have quite the large radius.
It has more of a balloon shape, made out of rubber and appears to have a neck on one side.
It seems like I really need to remove this object out of the chair before initiating assisted landing to avoid embarrassment or simply the downward sensors falsely thinking this is a safe place to land.
If there happens to be a mess involved, I might even need to consider the employment of a hard to find nowadays roll of toilet paper. But I don't think I need that here.