That technique will work fine. However be on your guard for air entrapment. There will be no route for air to escape to make sure you get all the air out the laminate to start with. Also it is easy to trap large air pockets laying down blocks of foam so care is needed again.  Scoring the foam can help give a path out for any larger air pockets.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Yes, you could do the B side at the same time too. Always helps if you are vac bagging though to push the core on evenly. If not, large piece of something rigid (ie sheet of ply) and a weight on top will help hold it down

Simple question :-  I am wet laying a flat 8ft x 4ft carbon fibre sheet with the intention of using a 28mm thick polypropylene core. Rather than waiting for the resin to cure, then applying adhesive to the sheet for the core, can I instead lay the core on the impregnated wet carbon sheet thus allowing the two to bond during the curing process ?