Premium seat foam from WCCC, back of seat

Hi
67 base with bucket seats. I’m redoing the seats, and i got the premium foam kit from WCCC.
Seat Cushion Foam - Standard - PREMIUM - Repro ~ 1967 Mercury Cougar ( 1967 Mercury Cougar ) at West Coast Classic Cougar :: The Definitive 1967 - 1973 Mercury Cougar Parts Source (cougarpartscatalog.com)

Anyone has experience with this setup ? I am a little confused by the Q&A on their website :

Nick Colchin Asked:
do I need the seat bolster (horseshoe) #31909 with the new seat foam?
February 24, 2023 5:00 AM

Answer
WCCC Support Staff (Junior) Answered:
Not that we know of, it should be moulded into the new foam.

I did a dry fit of the foam to the frame and it doesnt look like the new foam actually covers the back of the seat. When i stripped the seat, it was a different foam, much denser. WCCC actually have it listed, this is what i’m talking about
Bolster / Seat Foam - Used ~ 1967 Mercury Cougar ( 1967 Mercury Cougar ) at West Coast Classic Cougar :: The Definitive 1967 - 1973 Mercury Cougar Parts Source (cougarpartscatalog.com)

I have kept that piece of foam (but was planning to not reuse it given the overall state of rodent infestation) so all good, but i’m just wondering if I’m missing something or if WCCC support staff got it wrong on this one.

Thanks