Is it possible to add a "surface blacklist" option rather than whitelist? By default it can only spawn on Nauvis, and there's a toggle for "Spawn only on start surface", but you also have, immediately under it, a box where you can type all allowed surfaces, which only contains Nauvis. So unless you use a mod like Any Planet Start to begin somewhere else, that seems redundant. But really, I'd like a blacklist toggle, rather than whitelist, because if you're playing with lots of planet mods (such as the Razi Protocol modpack that includes like 40 planets), you'd have to type all the surface names manually into there, since the whitelist box can't be left blank. Would it be possible to do this? Also, I seem to be missing the big furnace, because it doesn't spawn on the map anywhere, and in settings it just appears as "entity=wsr-big-furance" rather than showing the correct sprite. That may need a fix, but it also may be because I'm running the aforementioned Razi Protocol and somehow that messes it up (even though as far as I know, it doesn't remove the stock electric furnace)

I'm not quite sure what you mean by the blacklist. Do you want buildings to appear on ALL planets except those on your list? I don't think that's a good idea—these buildings are pretty powerful and could break or drastically simplify the production chain on other planets. That's exactly why I made a whitelist and a separate checkbox for just the starting surface. Having 1–3 surfaces with these machines already makes the game much easier; I don't think it would be balanced to have these machines on all surfaces.

Regarding the missing furnaces. Are you playing with K2 or K2SO? If so, these mods remove furnaces from the game entirely and replace them with crafting machines that use furnace sprites. Plus, they mess with the recipes quite a bit. In that case, it’s easier to disable my furnaces so as not to break compatibility.
Or maybe some other mod in your build has removed my furnaces.