Okay, here's the results from leaving the pen nib down and uncapped for just over 5 days (122 hours). Very picture heavy.
Before writing, I disassembled the section, nib and feed. The ink and gold mix had completely dried. There were no signs of crusting on the feed, but the nib was pretty ugly looking. It appeared as though there could be some signs of rust. In the picture take notice of the dark crud at the nib's mid-section. In person, this looked very brown.
The breather hole in the section was heavily caked with gold powder, but did not look clogged as the gold was only resting on the "rod" rather than in the entire hole.
The cartridge converter suffered from some serious evaporation. There was only about .5 centimeters of ink left from a 3/4 fill. There was not enough ink left to make the pen write even after flooding the feed. I mixed the bottle before adding more ink. After a second flooding and some slight nib pressure (to presumably drag trapped gold powder from the nib slit), the pen wrote. It was very dry and slightly scratchy.
Skipping became an issue, needing to tap the pen every couple of letters. A second flooding of the feed (this time, without backing the piston off) the pen wrote very wet and smooth again.
The writing had intense gold sheen - much more than prior tests of leaving the nib inverted for a day. I presume this is because much of the ink had evaporated, leaving all of its gold in suspension behind. Adding more ink was enough to resuscitate the pen's ability to write, but left it a much more saturated mix.
Cleanup was significantly more difficult than standard ink. The gold powder did not present much of a problem, but the ink had became so dried and saturated that it took a significant amount of water to remove most of the color.
After disassembly, ink could still be seen on the nib. Held to the light, small amounts of gold could still be seen stuck in the feed. I put the section, feed, and nib into a sample vial filled with water. Shaking it removed much of the gold and dried ink. After a soak and further rinsing, it should be completely clean.