A stocking in a sleeper is a drawer. If the gift does not fit in a hand, it is not a stocking stuffer.
Ideas that fit
A pen that will not burst, a pack of wipes, a spare phone cable of the connector he actually uses, sunglasses with a UV400 mark on the listing, a small flashlight, a notebook, lip balm he will not be embarrassed to use. None of these need a policy meeting.
Skip glass carafes, scented candles, and anything labeled as a heater. The cab does not need an open flame or a mystery wattage in a drawer.
The sunglasses note on this site explains polarization and screens. A stocking pair is fine if the listing shows UV400. It is not eye care.
On a phone, this table moves sideways. The first column stays put.
Drawer-sized and not drawer-sized.
Fits a stocking
Does not
Cable, pen, wipes, balm, a small light
A glass coffee pot
Sunglasses with a UV400 label
A hardwired camera
A liner glove
A 1,500 watt inverter
Conclusion
One good small thing is plenty. A stocking full of junk becomes tomorrow's trash bag.
FAQ
Are scented products a nice touch?
Often no. A shared cab is a small room. Strong scent is not a gift everyone wants.