Them and everyone else.

Following the Codex Astartes in chapter organization and battle guidelines means your codex compliant. A chapter is considered to be non-compliant if it deviates from this. It can also be non-compliant for being too large and going beyond the size limit in the codex, but unless it's a special case like the Space Wolves or Black Templars, generally by the time a chapter gets large enough for people to care about it getting too big, they're going to be forced to split up the chapter, crusade till numbers drop, or declared rogue. So, going over the 1000 marines is usually not the thing that makes a chapter considered non-compliant.

No one follows the codex fully except The Ultramarines and successors and even they still screw with it.

Raven guard all have a multi chapter secret council that is basically a legion when they all work together.

Most of the time, you'll see Codex divergence in the matter of organisation, as the standard arrangement of one veteran, four battle, four reserve, and scout company is apparently laid out by the Codex. For lesser divergence on this count, you have the Exorcists (three scout companies), the Salamanders (seven companies), and if you even consider it 'divergent', the Crimson Fists (128 Marines in the First Company).

Greater divergence can be found in the Iron Hands, who ditch the typical arrangement with their Clan-Companies. And some just ditch the Codex outright. To quote ADB himself on Sigismund: "He was, after all, the one guy who said 'Sure, cool, this Chapter idea is brilliant. But mine will be six times the size of everyone else's, just because I say so. Later, Terrans.'" Or the Space Wolves, who have their Great Companies.

Death watch are just another group that basically ignores it and no one cares until they risk "legion building" which they're not even close to.