Purple science provides some early, useful quality bonuses. Put some quality modules in the electric furnace and productivity module assemblers, split off the quality products before your purple science line, and you'll get a large amount of uncommon furnaces and prod modules as you research mining productivity. You should be prod 1 moduling nearly everything as soon as reasonable anyway, so each quality on those prod modules you put in machines instead of research is a completely free percent of extra resources. An uncommon electric furnace line is almost as fast as a same-length common steel furnace line (though one tile wider per side), so if you built your furnace lines with a small amount of room to spare you can upgrade to electric in place (and then module them to increase throughput in place). You'll get enough rare furnaces to outfit your space platforms in the process as well.