It seems gold ore patches do not appear with Space Exploration enabled.

I have been extracting it from waste and copper for the first bit until I started to wonder why it seemed so rare

If you have BZ noble metals and SE, gold ore doesn't spawn on Nauvis. You should still be able to get enough to scrape by from copper and core mining, but you should be on the lookout for a planet you can mine gold from. I could also tweak some recipes with this specific set of mods so it's not so debilitating if you get unlucky with offworld gold sources.

If you don't have BZ noble metals, this is indeed a bug.

Completely forgot that BZ Noble Metals did that, and I have not reached space yet. I will have to work on my core drill setup and look for more copper while I get there...slowly, spaghett'ily.

Thanks for the great mods!

Recently noticed the same problem in my game too and unlike hraukr I don't use BZ Noble Metals. I do use two other bz mods though (namely lead and titanium). I personally don't mind it too much though. There's still ways to acquire gold like through copper, deep core mining and, with the DivOresity mod, through small patches of gold scattered inbetween other resource patches. It presents an unexpected challenge which I really like!