This is allowed yes, the rules issue is specifically with codex tech.

Pause buffering at the end of rooms means that the full door unlock time happens, while codex at the end of the room means that the in game timer is paused while the doors unlock if you open it fast enough.

Codex tech is a Hades 1 era term for it, but when the Book of Shadows or Inventory is opened the game doesn't actually pause. This means that, say, door unlocks, god encounters, or most critically player movement can continue to happen while the in game timer is paused. If you're in the discord, this post is a good example of it in this game: https://discord.com/channels/940392249844465694/1218621088049659930/1249154442515845253

In addition, an (old, mostly patched) example of the extremes of what was possible with this in Hades 1:

(Note for anyone reading who is not already aware: use of the codex when the in game timer is not already paused is banned in both games)

Putting a note in the description is perfect, thanks! When we verify the verifier can just adjust the version variable, as that version has been added to the boards.

If you join the discord (linked on this page), there is a formal process (recently added) for category suggestions. The details are fully listed in the relevant forum channels in there, but making a post that explains the category and links a video of a run would be a good starting point to making a category, as most of the community is more active on the discord than on these forums.

You do just need to get lucky, although you can have up to 10 rerolls (either starting with 10 and using none or using up to 2 and getting them back from Narcissus). Rolling 3 times makes it about a 1 in 2 chance I believe.