I also think you can get blaze powder somehow through industrial centrifuge and add it to slime balls
it takes a while to get the stuff though i think
Correct.
put a stack of redstone through the centrifuge and you get "eye powder" (correct me if it's the wrong name) Then take this and centrifuge it once more to get 8 blacepowder I think.
It's a nice alternative which could save you the trouble of even going to the Nether, or if you just can't find a blazespawner.
Along the way you even get other materials as well.
Slimes are easily found in swamp biomes.
If you can't find those, try out Factorization.
Put a bucket of milk + lime dye in the crystalizer and get slimeballs in return. (Takes a while but still better than running around forever, searching)
This is what's truly amazing about the pack as a whole. The possibility to do something in a different way by using mechanics from several different mods instead of using the same old ways as usual (Like when making the drill in IC)
Tedious you say? I say great fun and a great way to make use of the pack and not just a single mod.