Maybe I wasn't making our history clear enough. We've literally used every method we can think of possible to do things since ftb itself was released and even before then (shhhh don't mention the other thing) we're both knowledgeable with every mod that does something we consider useful and just decided that on this play through we'd focus on using force engines to produce all of our mj instead of what we've been doing many times before using boilers with all different fuel sources (our last playthrough ran entirely on a few dozen boilers being supplied with sugar coke from an underground coke oven bunker housing 500 coke ovens). We aren't even using power converters because, quite frankly, IC2 is useless to us past the Induction Furnace for it's speed.
We're looking for something obscure but useful to do. We've completed everything with Thaumcraft, IC2, BuildCraft, Steve's Carts 2, MinefactoryReloaded, Forestry, ExtraBees, Extra Trees, Applied Energistics, Thermal Expansion, Tinkerer's Construct, DartCraft, MFFS (not touching that one ever again), Advanced Solars, Compact Solars, ComputerCraft, Xeno's Reliquary, Factorization, ExtraUtils (admittedly probably haven't used this one enough but other mods do jobs better than this).
Some mods like Mystcraft have been omitted because we only use them for a certain item like Link Books now that the Ender-Thermic pump and the Laser Drill exist we don't need a lava ocean or a dense ores page. Other mods were omitted because we find the content dull or useless. Nevertheless we know how the mods work.
We want a big project to work on similar to getting a Fusion Reactor up, running, and automated back in Ultimate 1.4.7 but want to stick to Unleashed. Adding in another mod isn't entirely out of the question (except for GT because 1 we've already learned everything there is to know about it and it's machines and 2 we don't feel like messing with configs and item ids to get it to play nicely with TC which is more entertaining to us anyway).
We could make a mob farm for every non-boss-mob in the game but we've already done that several times before and have no current use for the items. We could make a farm for every tree in the game but we don't need the wood since we don't build fancy houses and such. We could leave everything behind and start fresh or restart the world but then we'd have the same problem after about a week of setup. We need something engaging, fun to use, and that would require us to do a fair bit of tinkerering with to learn it down to the last ingredient.