I have no practice if airport X-ray scanners are able to actually make imprints in metal visible. If not, you would need even way pricier X-ray scan equipment. Your adversary doesn't even know if all the X-ray hassle is worth the effort, unless you brag about your Bitcoin holdings.
It's easier to rip open the bag, torture you in a 5$ wrench attack and believe me, there are ways to make humans talk.
If take a random photo from the Internet, then on the X-ray of the luggage can see the well-known $5 wrench, on which the factory engraved text on the handle is slightly visible, which allows us to assume that, in theory, the text from the metal backup can be seen in this way.
It is risky, and the main problem is that you can't know for sure. You can't be sure whether XRAY scans are stored in any way, who has data to access them and so on. If someone does manage to read it off of the scan, you would never be 100% sure and you could not prove who the thief was and would unlikely be able to prove it. I would not carry an engraved metal piece through the airport. For this purpose the classic metal seed backups are better, as you can overlay the individual letters with each
othersother to prevent the readout or just reassemble it on the other side from a small paper note.
With that now I wonder how easy it is to crack a seed phrase if you have all the starting letters for 24 words but without order. That would be 96 individual metal plates with letters on them. Maybe someone good at numbers could check.