Been playing this again just to kind of challenge myself to see how much I could get through by memory and without using the quest book (it's really fast the 2nd time around! Granted, playing Infinity Evolved Expert Skyblock probably plays a part in it, too, and the fact that I edited the config to make bonemeal spread a mutating since I don't like that grind.
).
Just a few things I remember what I didn't like about Regrowth and could be improved on (just read about that updated version that's being worked on - it's funny, I was just thinking, "If there was a squeal to Regrowth made...") -
1 - The quest book being required to progress through some parts. Namely, getting copper/iron. Sometimes I just like playing without using the quest book. I'll probably dig around and see how to edit quest book scripts and go add some copper/iron runic altar recipe.
2 - Some agricraft plants are grindy. Seems like there's some plants (Botania) that take over 48 bonemeal just to mutate (again, I turned that option on), or, if I don't use bonemeal, it can take literally THREE HOURS to decide to mutate to the next set of crop sticks. It's fine on a server if maybe the area's chunk loaded (spawn chunks), but not as fun for single player.
3 - There's ores. Kinda.
I believe the lore said that there were no ores, so having the Mekanism/AcademyCraft ores just seems odd, and annoying when you're digging a base and there's an ore block in the way. Just a minor thing, though.
I'm hoping to see if there's more bee quests this time around. Last I played was nearly a year ago, and I know there was mention of more quests in one of Direwolf20's videos. (When I played it, the tech mods weren't even added).