my input for this thread after converting an extreme world save. (over 1,5, gigs.)
change interdiction torches to normal torches or be prepared for huge amounts of stone blocks
129 > 50
and make sure all forcefields are off. I just deleted all forcefield cores in my world to be sure.
the active forcefields give me an "immibis.ars.projectors.*********" block error.
this is resolved when all forcefields are off before converting.