I use Devotee Supreme all the time and sometimes switch to Construction Connoisseur for a second to get a few more houses built. Sometimes when I do this, my training speed which is 1.74k/m with Devotee Supreme shows 1.84k/m. Moving the screen left or right then returning fixes the error. My numbers are too high to really tell if this is a visual error or if I really do get an extra 100/m.
Also, most of the Devotion counters don't show earnings per tick which makes sense, but I think that Training Centre and Construction Company should show it.