I have 2 problems with this and the first is that it assumes everyone who uses your mod finds some value in the mana progression; I do not. I enjoy it because of the actual process of making its different magic/tech and you have just made it a hell of a lot more of a grind for me to enjoy that aspect than it was before because now, it is virtually impossible to automate the process without learning to use mod that are primarily tech mods (lava gen, assembly line for cakes) and basically mandate that people actively spend time grinding mana who don't know how to use (or like) those mods and thus people like me can no longer set up a mana gen and go mess with another mod like thaumcraft while we wait for a few hours to pass by that we need to have enough mana to get started on the first few tiers right away.
You can automate every flower, bar the Thermallilly and Rosa Arcadia, using nothing but botania. No other mods are required, botania gives all the tools needed. Instead of using a field of dayblooms, why not set up a simple redstone system using a dropper, a wood pressure plate, a redstone torch, and a piece of redstone to feed half a dozen endofflames. Semi-automate the process, then dump in extra coal from mining or charcoal from a tree farm. Doesn't even need to be an automated one, a manual tree farm will provide a lot of fuel. That will net you plenty of mana to work with. Fully automate, or at least semi- automate it to the point you only need to check on it once in a while, and you'll be making enough mana to sate all your needs.
You say all of these things under the belief that your decision is justified by how game design works, but under game design standards, your mod is flawed at the core anyway. You require people to grind for hours to create the illusion of content instead of providing actual content. If you want your experience to feel engaging, maybe you should redesign the mana system or just get rid of it entirely. It seems like you want people to be actively engaged in your mod's progression anyway, creating a buffer between player input and game output like the mana grind is an old trick that is commonly considered questionable game design today. It's something games on older hardware, especially RPGs, used to do to make a game seem longer because they didn't have the storage space on old carts to make real content and it is still used today to cheapen the expense of making legitimate content in games and I shouldn't need to tell anyone that is a dishonorable motive to do anything.
This is actually personal preference. To some, building automated systems to generate mana is enjoyable content. To me it is like trying to solve a logic puzzle, identifying tasks that need to be done, working out how to automate each and every part using the simple tools at hand. Dreaming up redstone logic, planning out intricate systems that work hand in hand to achieve a greater goal, working around some limitations... That is enjoyable content for me(Granted, I am a self proclaimed Madman). Given the ruleset Vazkii has in play with Botania, creativity is heavily encouraged and rewarded. Think of a cheap way to build a tree farm? Have easy mana gen early on. Learn the value of Daylight sensors? Crop farm is now possible.
And, to turn your argument back on you, making dayblooms would have been just as grindy. Late game items needed a lot of mana to work, and dayblooms, nightshades, and hydrodrangias would struggle to feed that. That was the point, so they player had to move away from the flowers that produce a dripfeed of mana to the real powerhouses. To even consider doing anything, you needed hundreds of the passives. Is making those not grindy? Making one simple system that takes five minutes to build, then feeding it fuel from time to time is comparatively far less grindy, and nets more mana in less time.
The thaumcraft guy realized his TC2 design was flawed for this exact reason and that was why he started redesigning it and why TC4 works on a much more interactive way now. Plus, he didn't just want it to be "just another tech mod" which is what the energy maintenance mechanic is commonly associated with.
Energy is not tech specific. Energy is nothing but a arbitrary resource given context and a purpose. This purpose could be to limit the player, making them think about their actions and choices and how it impacts their energy supply. It gives way to personal preference, and can encourage the player to make compromises. Do you spend that precious energy to make ores, grow crops, or fuel furnaces? You could do all three, but at a greatly reduced speed thanks to low generation.
You see it as a needless grind, I see it as an actual mechanic to bring into account. I've built small temporary systems to provide quick bursts of mana using a fuel source I had an abundance of, yet did not have an automated supply. I would eventually run out, but the mana produced before that happened would keep me going, and help fund the next generator that was fully automated.
Personally, I don't like tech mods for this reason and because they are such a complicated hassle to set up with all their pipes and wires and crap so having this become even more of one with its mandatory integration with other mods in a modpack just to not have to go back and forth in a garden feeding cake flowers all day has killed my interest in using it in the future.
But I was linked to that blog post by someone who does like tech mods and is really unhappy with this direction, in fact nobody on our server, tech fan or otherwise, is interested in dealing with the extra grind. We are obviously not your target audience and therefore you have no concern for us so this is likely an ideal outcome for you.
Again, you don't need to use other mods. You can fully automate cake production and placement for mana gen, and I have already done so. Is it easy? Depends on your outlook, but it has provided a large amount of mana to make it worth my time while I enjoyed building the system because of the trickiness.
A note: If you really want to use botania and don't want to bother thinking about complex or even simple automation or semi automation, as I understand it is not everyone's cup of tea and is personal preference(Please do not take my words as condescending, as I know they can be read as such. As I said, it is personal preference and I understand not all will agree with my views. I am a Madman, so I am fine with that.) , You could hunt for or add a recipe for(Or cheat in) Overgrowth seeds, They stop passive decay on any of the passive flowers planted on the enchanted soil it makes. I would personally consider that a waist of Overgrowth seeds, since I have much greater use for it's main feature in boosting all other flowers.