It’s crazy that no one has the answer. And it’s not clearer on the site…
They only specify that :
“If you sell or gift your product to someone else, that person (“second owner”) is eligible for in-Warranty repairs and replacements as long as they can demonstrate that the device was registered for this warranty by the original owner and can show proof of purchase that We or one of Our authorized partners issued to you (transfer warranty). The transferred warranty cannot extend beyond the period of your original warranty from the date of your delivery.”.
There is no reference to the extended 5-year warranty (I did register the device on the site to benefit from it).
Nothing crazy about fellow users not commenting about legal obligations of somebody else
The relevant part from warranty documents
– In case You sell or donate Your Product to someone else, this person (“Second Owner”) can benefit from In-Warranty repairs and replacements as long as they can demonstrate the device was registered for this Warranty by the Original owner and they can show the proof of purchase We or one of Our authorized partners issued to You (transferred Warranty). The transferred Warranty cannot extend beyond the period of Your original Warranty from the date of Your delivery.
You also mentioned you want to tinker with the invoice erasing some parts of the information.
Please do not expect the community members to assess the legal consequences of that.