Apparently, this is no longer the configuration of the refreshed 2022 model X. Our mobile service tech said that if replacing the cabin filter did not help, that do need to replace the HEPA filter and suggested we do that at the dealer. He also stated that cleaning the evaporator has not proven to be an effective fix and would be a waste of time and effort.
I came across images from another 2022 model X owner who did remove the frunk bin and still was unable to locate the hepa. Apparently it's not so easy to replace anymore and it DOES need to be replaced to stop the smell.
Unfortunately, our HEPA started smelling bad after about 12-15 months in humid Wilmington NC.
-Zach