Java Jive wrote:

Difficulty in getting the beam to be projected at 90 degrees to the wall
at the height that the work to be done requires;

Tripod

Floating beam wobbles, while ...

Mine only wobbles if you jump up and down near it

difficult not to move beam off level when locking the device
to stop the beam wobbling;

Better to leave it unlocked so the self-levelling can do its thing, they
tend to flash if the position is too far out for it to cope, the locking
is only for when not in use, or if you somehow want to project a
straight (rather than level) line without it flashing.

Dimness of beam in good lighting.

Red ones are generally ok indoors, you'll have to wait until dusk if you
want to use outdoors or use a reflective target, green ones look much
better never seen one in the flesh.