I believe it is what it is purported to be, nothing less nothing more.
The idea that a relic forger was capable of such detail and accuracy in the Middle Ages is laughable. Further, at a time when any chicken bone could be produced as the bones of a saint, WHY WOULD ANYONE BOTHER?
Yes, the idea of a conscious forgery seems to vastly fail the plausibility test.
If believing that this is a genuine relic our response should be hallelujah to the Lord.
The devil wants to detract from the glory of God and a mock relic would do that, I believe. God will forgive us if we are mistaken because our heavenly faith doesn’t rest on the shroud. Rather, the shroud is acknowledged as another pointer to the Lord by our heavenly faith.