Is this truly considered a triple impression?
No. The two additional partial design transfers are from Tagging Ghosting.
Would it be uncommon?
Yes, double tagging ghosting is not common.
I again direct you to https://www.efocc.org/Resources/Hot...AA_Cover.php
for some guidance. The subject of this thread can be found in variety 57 on the listed EFOs, under Freaks.