Not to put a damper on your post, but 1mm, possibly... but 2mm might not be too possible, when the chassis is barely 3mm thick as it is. lol
I definitely want one of these new BCE chassis, either way!
I get what you are saying, the tlr chassis is milled at the battery area in sections and the BCE is completely milled for the entire battery to drop down into. Looks like it is double stepped down,pads go lower and battery lower. I don't have mine in hand yet to measure.
