- penalties for having multiple schools innervated might be expanded to include modifiers to reserve utilization efficiency. For example, as long as you only have abilities from a single school you only use 7 reserve points to restore 10 actual psi points. While 2/3/4 schools would increase it to 10/15/20 points of reserves for 10 psi points.
I'd caution against that sort of thing on the grounds that it directly rewards the most boring play possible, and further punishes newcomers to the game who don't know how to optimize every action. As it is, I can't say I'm a fan of increasing psi cost combined with global scarcity of psi points, because it actively punishes people looking for variety in how they play the game, and that's just poor design. With additional reward for single-school, you provide a strong psi bonus for builds that only dabble in psi, or use a minimal selection of it. The cumulative effect of higher costs and reduced reserve efficiency, combined with the current inability to restore reserve during combat, nearly guarantees that in any difficult fight, bringing a generalized loadout will result in depletion and failure. If you want to do the same thing every fight for the whole game, there's tin can AR, already.
Reducing effective skill values for multiple schools - because it's so very hard to magically cave wizard in several different ways all at once and you mix up the tiny details and as a result don't do everything just right - would have weakened psi generalists compared to psi specialists without also mechanically punishing players for trying out new things. We've clearly seen that Stygsoft can add in debuffs quite easily, so causing activation of a psi school ability to effect a psi school debuff (penalizing skill values, durations, and/or psi costs) on the player would have been simple and it could have done for psi generalists just as well as the current system, but without also sucking quite as hard as the original idea does. But having "psi bullets" as an actual consumable resource, and then rewarding players for not using variety, and punishing them when they do use it, isn't an effective way to reign in power; it merely reigns in player agency. If you can't manage the first without disturbing the second, then you don't understand the system you're changing.
I can't help but agree. The sheer versatility of a pure psi character was one of its greatest strengths; while having a tool for every situation was one reasons pure psi was overpowered, it meant that there was always another way to handle the situation. Psychosis Psi was my first dominating build, and when I died, I would constantly take a step back, bring up my spell list, and think up a better solution. The versatility forced me to improve and engage with the game's deep systems and rules, rather than trying the same thing again hoping for better luck. It's diametrically opposed to the save scumming that the game currently rewards*. The new system encourages you to find a specific set of actions to repeatedly perform, and punishes players from deviating too far from using just one school, which is problematic since "Which one of the three** psi schools is best for this encounter" is a far less compelling question than "How do I leverage the abilities I have".
I'm worried that the psi cost increases along with psi reserves will leave dedicated psi characters not only limited in their accessible toolset, but also simply unable to survive marathons of combat. Once the reserves are tapped, they simple hit a brick wall where they're waiting on the cooldown of psi boosters before being able to do anything. Sadly enough, the in-game solution to the "running out of reserves in long combats" is zone abuse. The strategy*** will be to walk to the edge of the zone once low on reserves, head out, take a hit from the psi bong, and re-enter the fray. Sure, there are AP penalties, but cave wizards have no other option, aside from using cheat engine to respec their skill points.
In terms of solutions, I would prefer a feat that allows some restoration of reserves rather than a consumable. This is three-fold: First, spending a feat incurs an opportunity cost, which tunes down the power of dedicated psions, which seems to be the ultimate goal of the update. Second, it makes your character more defined, and creates a real identity for the "Dedicated Mage" to separate it from "The guy who picked the best school or two and has a backup plan when s/he run out of psi". Third, in the late game, the monetary costs of consumables becomes negligible, and another resource to manage will become more about inventory management than cost management.
*Because functional builds demand specialization that limits what your character can actually do well.
**Three instead of four, since Temporal on its own requires a weapon for damage, which the archetypal pure psi will avoid.
***That the mechanics flat-out encourage!
