The only correct source for the sticker is the flat version:
* You design the flat version with the formed part underneath as template (counting in the 0.25 LDU for the stickerback) for your splits.
* Split and sub and rejoin them for the formed sticker.
* There is no need to remeasure the formed sticker, as it is based on the flat version we know is correct.
https://library.ldraw.org/parts/25778 has been done this way.
w.
* You design the flat version with the formed part underneath as template (counting in the 0.25 LDU for the stickerback) for your splits.
* Split and sub and rejoin them for the formed sticker.
* There is no need to remeasure the formed sticker, as it is based on the flat version we know is correct.
https://library.ldraw.org/parts/25778 has been done this way.
w.
LEGO ergo sum