They hide the CoT because they don't want competitors to train on it

Training on the CoT itself is pretty dubious since it's reward hacked to some degree (as evident from e.g. GLM-4.7 which tried pulling that with 3.0 Pro, and ended up repeating Model Armor injections without really understanding/following them). In any case they aren't trying to hide it particularly hard.

> In any case they aren't trying to hide it particularly hard.

What does that mean? Are you able to read the raw cot? how?