I want to do some tweaking on Controlled Plasma.
I love these thoughts. Big thumb up. Yes.
I want to add Naval Tactics as a prerequisite for Screw Propeller. I noticed that SP has only prerequisite (Steam Power) and NT has only one exit point (Grand War). I would prefer if every tech had at least two exit points. I've already made sure that every tech has at least one exit so there are no dead-ends. I would prefer if every tech had at least two prerequisites and two exit points, but it's not absolutely necessary.
I less love these thoughts. My first reaction is that... one thing we have right now with RoM is that advancement, in particularly materials science, is removed from necessarily prerequiring a military motivation for having that advancement. Each way that we constrain alternative history to just be [some military doctrine] -> [the technological basis for another weapon], we lose that.
That fact probably seems less objectionable to different people. But I need it to preface the second worry I have, which I do think is objectively pressing, but speculative. And that is... I've had an intuition that your regularization of the tree, which you have sought in the name of 'removing the gilded edges' I believe was your term, has the risk that, if you actually succeed in this regularity becoming pervasive, it will result in the gameplay becoming repetitive. Like this: If the structure of tech requirements is really so rulebound from start to finish, it would mean that the thought process that occurs, when proceeding from an arbitrary point in the game, will weigh what one route through techs will do versus another route through techs will do (of course), but the factors of one route and the factors in the other route will be
the same decision, you see what I mean?
Might be very distant from this one instance of change.
One thing I can definitely do , profitably, is work out any mathematical necessities of a tech tree's entry points and exit points. Like, you know, I bet that if you stipulate a peerage of techs that have just one prerequisite, that implies the previous generation can't have had more exit points since, from the other perspective, they equal, right? It would give you more penetrating understanding to work with, in designing any regularities like the 2-2 rule you just mentioned.