Technics 1200G VTA Lock or unlock is the question?

Someone else perhaps on Vinyl Asylum recently suggested that the locking mechanism, because of the way it intercalates with the threads on the vertical shaft, causes a slight change in VTA when engaged.  Could your observation be due to something like that?  Otherwise, can you think of an hypothesis to explain your observation?

There's an interesting article in the current Stereophile by Art Dudley about tightening things and deformation of structures etc. Of course, overtightening has always been anathema with mechanical reproduction systems. 

 I locked it again and it sounds fine.  It did seem to have some benefits in some ways though, maybe for some circumstances.

Wha....?Your opening statement was based on one trial?Which is it that seemed "to have some benefits in some ways"?  Locking or not locking?

@lewm +1