There's not much point arguing the toss over this because it's pretty soon to be water under the bridge.
All I know, having imported WLT over several years, is that the process (up until the last month or two) is that, after clearing Customs, you'd receive a letter from MPI telling you that there were three options - have it heat treated (and up until quite recently there was only one provider, 'Flick'), have it returned to the vendor, or have it destroyed).
Only since Fedex started handling it a month or two ago, had MPI agreed to having it 'visually inspected'
When this was done it usually happened in a few days. And only if the visual inspection showed some 'contamination' did you have to then pay for heat treatment. If this happened you paid twice -for inspection AND treatment. In the past, most of the time the box hadn't been opened. It just went straight through Flick, etc with the seal in tact. (Which is probably why they never knew in most cases that they'd incinerated the contents).
As I was saying above, this is now pretty much academic.
And I was only offering the thought to anyone with a parcel still in transit that if MPI would accept it, a visual inspection was a better choice than heat treatment.