When I play these packs, there always seems to be this middle stage where I just have to mine, and mine, and mine, and mine. At that point in progression (I guess the cusp of mid-game) I just get bored and either cheat or quit playing that save altogether. Tips on pushing through that stage of the game?
Identify the thing that's become frustrating, and set yourself a goal of automating it instead of continuing to do it manually. For me, even if I still have to do some of the tedious thing (like more mining) for a while to build up the resources, having a goal and a plan for dealing with it helps a lot. If mining is becoming a pain, figure out what you want to do for automated quarrying, make a quick list of the resources you need to accomplish that, then get to work. Now you're working towards a goal, rather than just seeing yourself short of gold or whatever and trudging out to do some more mining because you "have to".
Also, assuming it's in your modpack, make yourself a clipboard (I think it's from bibliocraft). I keep a clipboard stuck next to my front door, and as I come up with projects, I add them to the list. When I get bored of whatever I'm currently doing, I look at the clipboard for something that sounds more interesting to do for a while.
Anyway. That's what helps me when I start to get bored.