It is possible to attack NLHE bet sizing from a GTO perspective. A special case of this gives an interesting result. Consider another 'half street' game where the in position player has the decision to bet on the river. Clairvoyance as Chen calls it, is the situation when your opponent's hand is face up AND it is always a bluff catcher. This occurs often on the river in NLHE against poor players. You know whether your hand is good or not, and thus the only question is what size to bet (and obviously which frequency to bluff). Note that this means we never have a reason to check a hand with showdown value because villain's hand is face up.

Remember, in GTO terms, we must bet with a ratio of valuebets/bluffs such that villain has the same EV for calling versus folding (0 EV). If our range is skewed towards value hands (say 60% value and 40% air), then it is correct to bet our whole stack with our whole range. Yes, we should bet as much as possible with every hand and bluff with the appropriate frequency depending on bet size. For example, betting 2x pot means we should bluff 40% of the time.

Now some intuition to explain the result. The obvious answer seems to be for villain to call 40% of the time and negative our bluffs. This is wrong. Villain should actually fold 100% of the time. Even though we're bluffing, our range is skewed towards strong hands and thus we gain more and more for larger and larger bet sizes. To see this solution more clearly consider the case of villain calling some %, and think about our counter strategy of varying bet sizing for bluffs versus valuebets (ask me if you can't see it).

The point is that when villain's hand is face up, we should valuebet all-in with everything that beats him, and bluff accordingly. This isn't really a new concept. You may have heard the concept referred to as " the showdown tax". For example, on the river with a PSB left, bet every better hand (and some % of bluffs). Everyone is a calling station these days, so they tend to deviate from the 'always fold' case when your range is strong. Exploit that!