In my case I use Blum soft close slides, but most slides of the same style from other sources are similar. The allowance given is typically 10mm for the opening over draw width or 5mm per side. I can't see why you couldn't dado a 4mm groove in the cabinet side to set the slide to give the tolerance your looking for. IMHO its a lot of extra work for an extra 8mm of space but if you want to give it a try why not. You aren't giving much room for the inherent play in the slides so atest run would be highly advised to prevent rubbing.
John