After exactly 55 hours of running GregTech Community Pack I did some more things and learned some more about GregTech.
My issue with the HV blast furnace was due to the pipes used. After switching to large aluminium pipes the four MV generators for it run flawlessly even under load. I forgot that there's that little note in the quest book that says "2 steam = 1 EU", and then got the hang of the whole GregTech power system, meaning that I can calculate exactly how I should set up my power generation by taking into the equation how much power everything consumes while running, how much steam I can produce, and how much throughput my pipes have.
I've rebuilt both bronze boilers and pyrolysis ovens to share walls, so that they are more compact, however I should probably completely rebuild the entire setup to be even more compact and to have less pipes to run to power everything, since the main machinery section is stuck like two chunks away from the boilers. And speaking of those, I've rebuilt everything and moved those somewhere else, got rid of the LV steam turbines for the most part since now I understand how that shit works and how I can just use a step down transformer in the MV grid to power all the LV stuff I have, but it's still a mess, but I'm slowly learning and getting the hang of it.
I've made a little shitty contraption to produce hydrochloric acid or whatever it was called, it works fine but it doesn't produce enough oxygen for the reaction to be smooth, so I just hoarded oxygen that I'd normally void from the electrolyzer to supply it to that. Got two full stainless steel drums of that, and an almost full stainless steel drum of hydrochloric acid. Yes I'm still mostly crafting shit manually like a troglodyte.
I've processed all the ores I've had to process, which is why I was idling for over two days, and I'll probably have to get some silent low power draw computer to host the world on that if I want to really get to getting through this without leaving my PC on overnight all the time, I've created the final HV circuits that I could from the MV era quest book section, and the next step is HV, but I still need to figure out better power generation and automatic oil processing since I will need a shitton of polyethylene moving forward. The quest book is suggesting that I'd move away from steam at this point, but I have no fucking idea how to create a perpetuum mobile with that like I did with the pyrolysis ovens and bronze boilers.
That's enough GregTech for now, and I guess I'll come back to it in a few months whenever I'll feel like going deeper into it. It's pretty fun so far, the only main tedium I'm really experiencing is the lack of power to scale things further. Besides that it's a good experience for someone who likes the 'tism factory mods, and the Community Pack's quest book is a great lead for a beginner like me who only ever delved into IndustrialCraft2, BuildCraft and the Thermal series. I just wished there were more meta guides for it, but I guess with the aforementioned GregTech version cultism it's a hard ask.
By the way, I recommend installing the Squake mod. I just bhop around the factory flat that I made or along it's one block thin wall when I'm waiting for shit, or when I just want to get from one end to another. It's very fun.