About size of flattened sticker and formed sticker

[Orion Pobursky]

Do flattened and formed stickers have to be the same length?

Yes but exceptions can be made

Do you need to round the stickerbacks to the nominal size of the description?

As an author, I would expect the actual sticker back dimensions to be exactly same as in the description. For normal parts, 3 digit precision is plenty with very few exceptions. So, to answer your question: yes, without exception.

I think the spec is clear on both these points but I'm willing to clarify if needed.