Punching down CAT6 into patch panel - how much of the pairs can you untwist? (30-40mm too much?)

We are punching down solid-core CAT6 cable into a CAT6 patch panel.

I've been trying to strip as little jacket as possible and get the twists very close to the jack - however, it's quite tricky.

It would be much easier if I could strip more of the wire, and untwist more of the conductors (e.g. 30-40mm).

However, in order to meet CAT6 specs - how much of the pair can you actually untwist?

Does it make a big difference in terms of noise/performance etc?