I'm thinking you'll be good with the rubber manifold connectors holding the weight of the filter, your unit can't weigh any more than pods, and we haven't heard of anyone loosing a rack of carbs on the road because the pods were too heavy , so that won't be a problem.
As for the weight of the unit on the back end of the carbs , they are clamped onto the carbs in 4 places distributing the weight across all 4 carbs. The only thing that would make it a question in my view would be the condition of the rubber connector to the air box. Are they old factory ones with big lips surrounding the airbox carb openings and stiff ? Or are they really soft aftermarket replacements that fit a little loose ?
I'm thinking that if you are worried about it rattling off you would probably should mount a strip that would connect the rearmost of your filter probably at the powder coated aluminum air inlet cover to the forward 6mm /10mm head bolt on the top of the frame, under the seat,behind the rear tank mount You may be using it to bolt in the electric tray...is it possible to use the stock airbox mounts under the electric tray at the forward position to catch a secure a spot on the new airbox by securing it under the frame with a longer bolt so it doesn't disturb the tray? I think if it worries you it should be addressed. You are doing a beautiful job on this build , it has been worth the wait.