"" I leave the crumb tray in my CSO all the time ""
does condensed water accumulate for you if the crumb tray is always in, preventing draining into the tiny tiny tray ?
the crumb tray seems to do more than collect crumbs. try toast at the same setting w and w/o the tray
for toast it seems to reflect back heat to the bottom of the toast.
decided for your self re toast.
a dark matt may not work as well, but you'll have to try that yourself, as i do not have one