Boundaries B climbs stair outside 16x16x16 but different behaviour head on and head off.

Being doing a fair amount of work on B working outside the 16x16x16 matrix. This short video illustrates behaviour climbing a tall stair outside the matrix. The difference in behaviour with head on or off is, to me, quite startling. I've drastically edited the climb with head on as it takes for ever.
To work B has to start from 'white space' within the matrix, totally enclosed with no connection path to the outside world. The destination has to be white space in the outside world but in line with the staircase.
Why does B do an impersonation of Quasimodo when his his head is on? Is this a cue for a level entitled 'The Hunchback of Notre Dame' ?

 

Sounds logical. Presumably when freed from the weight of his head he doesn't tip forward, walks upright and a a much faster pace. Assume placing a cylinder on his body instead of the head should also result in the Quasimodo syndrome. Will try it and report back. Thanks for replying.

 

I tried a pillar plus an eyeball, same result as you. Bit inelegant and not very practical.