Rear Spoiler Weather Strip needed?

is the foam weather stripping under the rear lip spoiler (not the sti spoiler) on the wrx needed? i got a replacement spoiler and the foam is way thicker than what was on the original wing. guessing maybe its from being compressed with age. however i am not able to get it to sit where the original was and theres tons of chips and a few rusty spots that were hidden by the original wing but cant get the new one to sit close enough to the trunk to cover

wondering if i can trim some off, or maybe remove alltogether and use something like the black 3m weather strip adhesive in its place that way it can compress to needed thickness and will harden after a few hours