Pedal Stack and Crank Length

Kind of a weird/stupid question but will getting a set of pedals with more stack indirectly shorten your crank length? Example: speedplay zeros have a listed stack of 11.5mm with Keo Carbons being 15.7. Now do those 5.2mm mean anything in terms of crank length or do they have no effect at all? Don’t beat me up too much if this is a dumb question. Thanks.

doesn’t effect your crank length, does effect your knee/hip extension at bottom dead center and top dead center.

the circular path the pedal follows is still the same size - it just changes the vertical position of the platform and hence a saddle height adjustment would be required…

thanks…after a few more minutes of thinking i figured it out.