A good hand screw locks it down the best from my experience.

In my van I also have a quarter inch hole through the cabinet. That then
lines up with a hole in the table leg I have drilled while the table is in
varying positions. For instance standard all the way down, all the way up
to access the horizontal cabinets and then a setting where it is over the
sink to gain easy access to both closet and cabinets. (This one is best for
packing.)

I then use a pin with finger pull to "lock" the table in place through the
home in cabinet by lining everything up. It's solid and doesn't rely on the
hand screw whatsoever. Takes a little time to get used to the position to
get it in but not to bad.

Best, bin intrusive stock looking way to lock the table I have seen.
Ryan
Asheville, NC