Inset or overlay work identical, when parked there is no sag, the sag only occurs when the slide is extended. For drawer front adjustment I use the tried and true Blum fastening system. See below if unfamiliar.
I use blum movento and grass dynapro. Drawers still sag up to 2mm if heavy object are inside. But I only build frameless full overlay with 3mm reveals.?
I am not sure how inset cabinetry works. If the runners pull the drawers box in and you¡¯re reliant on the bumpers stoping the drawers face and that¡¯s what makes the drawer face flush with the face frame. I could see how the drawer wouldn¡¯t sag.
