I guess Ive been toasting wrong for some time.
I have noted that the bottom of my toasts are lighter than the tops.
the true middle of the space is inverted rack , i.e. " lower broiler position ' regarding their pics.
however , there are three heating elements on the top of the space , and two on the bottom.
I changed the rack position and have an experiment in the CSO as I type
result :
very even toast !
no Idea how long Ive been doing it wrong