Direct copy and paste from Vazkii's site:
Liquid/Fluid Mana
Here’s another perfect trainwreck. Let’s remove the whole purpose and depth of the mana transport system and replace it with streamlined pipes and tanks and fourth dimension teleportation devices, sounds good! I’m not going to bother commenting on this one, it should be painstakingly obvious.
Also I don't recall ever seeing or hearing anyone from Mojang say that they didn't want anything to do with those features(wands, multi-use potions, etc. If I'm wrong, please prove me so.
If mod authors TRULY didn't want anyone to create mods that added features that went against their mod's design intents, then they would keep their mods closed source and not develop APIs for them.
When a mod developer opens their mod and makes an API, they understand that this will allow ANYONE to create pretty much any mod that does thing with their mod, whether it fits the mod author's original design intent or not.
If you, as a modpack developer, don't like certain features in mod addons, such as Technomancy, then here's an idea: don't add the mod to your pack. And if you like one particular item or feature in a mod, then add the mod to your pack and disable everything but that one item. That's why configs and minetweaker exist.
If Vazkii truly has a problem with Technomancy's fluid mana system, then so what. If it's really that big of a deal, then he should just close that part of the API/code. But he didn't, and because he developed his mod in a way where mana can be manipulated by other mods, then he realizes that people could potentially develop mods that do things to Botania that he doesn't like. Not accepting this fact would be naive.
That is why the modding community is just that - a community. It is up to mod developers to communicate with each other on good terms to help find balance between mods and their addons. It is also up to modpack developers to provide heavy feedback to mod authors, and the authors of those mod's addons, to help find an agreeable balance. Furthermore, it is up to modpack developers to create a pack that is well designed. Or, they could not, and just create a pack where you can mine stacks of diamonds within the first hour of playing, resulting in a gameplay experience that causes you to get bored within a few days.
With that being said, I personally like the idea of liquid mana, but only because it actually fits into my modpack's design.
From my personal experience on my modpack, even without liquid mana, I have noticed that players actually tend NOT to use Botania for anything other than grabbing the artifacts and baubles. I would really love to see players use Botania for things like accelerated crop growth, inventory management, material production, etc.
But they don't, and that's because the vanilla mana transportation method is cumbersome on modpacks, especially when players have factories, farms, etc. that cover large areas. They would much rather, for example, slap down a ritual of the green grove, or use vacuum hoppers. With fluid mana, I feel like that more players would actually use Botania for something useful/integral in their factories and farms. I for one certainly would. Setting up mana spreaders to move mana from my central mana production area to each of my farms for agricarnations is, imo, more cumbersome than going through the trouble of making some lilypads of fertility and setting up openblock sprinklers.
However, I already have a ME network setup to run to each part of my factory. If I were able to pass mana through my ME network (thanks, extra cells), then I could much more easily use Botania to help speed up crop growth.
If I, at any point, feel that liquid mana makes Botania *too easy*, then it is up to me to A) communicate with the Technomancy devs to help find a balance or B) use the provided configs to set my own balance. Technomancy already includes config options for the mana and blood fabricators, so I imagine there will also be one for this item as well. And believe me when I say that mana and blood fabricators, by default, are pretty damn expensive in terms of power (RF) to run. With my machines and 2 mana fabricators, my 17x17x17 big reactor with 4 ludicrite turbines were *barely* keeping up.
TL;Dr when you make a mod and throw it into a modpack, your results may vary. Stop being lazy and use configs to balance your pack.