Yes.
First step was to get a digital copy (the B&W forums has a link to one a local authority prepared). That way you can keep a copy for yourself and to give to the assessor (who not only won't have one, but isn't allowed to see one
) when they call, or when you go.
Ideally everything - every single letter, follow up letter, appointment, correspondence - should be scanned and indexed, so it can be cross referenced in the main form. So if you are stating you are unable to do something, or find it painful, there are letters from doctors supporting the claim.
I did DWs form - it ran to 56 pages with references. I rendered it exactly as the original printed form, and got a local printshop to run off 3 copies on decent paper. I recreated the QR code too and put DWs NI number and "Page x of y" on the top of every page so that when they received it there was no excuse.
Obviously keeping an electronic copy means that if (when) they lose it (notice how hard it is to prove delivery ...) it's trivial to run off another copy.
Last tip from B&W was to sent a duplicate copy to the "decision maker" - which is the address on the top of the letters you get from DWP. Personally I made it clear in the overall correspondence that they had been "cc'd" in.
As I was filling it in, I roled-played making my way through a minefield, and tried hard not to misstep.
DW was awarded full PIP. At the assessment, the assessor, because they had no copy of the submission had no sight (no pun intended) of DWs certificate of blindness. Since I had a copy with me I offered it to her, but she's not allowed to accept any paperwork from the claimant. I offered to email it to any address, but seeing it for real was sufficient.