Just for those who hate all the mushroom/magical forest biome spammage with BOP on this modpack: I noticed on the thaumcraft config that the magicforest biome weight was default at 80 (BOP leaves most biomes at about 15) so my world was inundated with massive magical forests/mushroom biomes (and no oceans=therefore no abyssal stone). I tweaked the thaumcraft biomes down to 20 and it seemed to have balanced out my worldgen to something more interesting. I moved all my stuff to the nether, deleted my world (keeping my nether intact) and regenned a new seed and now it's all good. Building a new base with minimal machines for now, I packed up everything into barrels/silver chests, dolly'd them up and stored them.
Problem with the default spawn issue was never finding a truly beautiful spot to build a base, so I was attempting to limit my "base crawl" (you tend to do that on the harder modpacks as you accumulate more infrastructure without proper planning lol).
Happily building a Robert-MaCall inspaired floating base over a coral reef a mere 500 blocks from spawn and all's going well. Thanks for the awesome modpack!