There are dedicated spacers listed in the Ducati parts catalogue (71614961AA).
I converted a UK Bike Euro4 shotguns to Termignoni belly cans recently but had already removed the pillion pegs & an Evotech side mounted exhaust bracket was doing the job of keeping the heat shield away from the seat cowl. I opted to source some economically acceptable 5mm thick spacer washers from a well known international online bidding site. I'll place these between the M8 cap screw head and the seat cowl as there is an alloy fitting sitting just proud of the seat cowl to lock it against. These two screws are just holding the heat shield in place in my case whereas an anchor to support another human being probably merits an engineered fix.
I've asked someone with the Akra system to check what's been installed by the Dealer.
What you're looking for won't be too far off a simple washer/spacer.
Not sure you'd get me back there (even with the spacers).
