My short amateur review:
The card looks nice. I did a quick attempt to remove the sticker without damaging it with a normal knife and got an area of about 2x0.5 cm off without bigger problems. I only cut from one direction so I think it might be possible to remove it completely with a scalpel whilst cutting in a circle. The sticker could be reapplied and still left the security pattern when I pulled it off again. It was easy to scrape off the sticker leftovers with a knife. Its easy to remove the print with wire wool, but I dont think that will be a problem with regular use.
My uneducated advice would be to perhaps rough the private key area up a bit and apply the seal with some pressure?
Even though no one likes to hear about issues like thakt: Thank you very much for your input!
We would love to investigate what allowed this to happen on the specific card and replace it. It would like you to ask to get in touch with me at matti (at) bit-card (dot) com.