Looks like the heads broke off due to defective spokes, or metal fatigue from them being loose and moving. Have the spokes replaced, the wheel trued, and the tension set by a shop. No lube. I have 6000 miles on my RadMini with no spoke problems, but I do check and adjust tension as a part of maintenance.
The spokes arrived. The half-pound package took 12 days to leave China, 3 days to cross the Pacific, and 6 days to cross the US.
I'd measured the old spokes, but the new ones seemed much too long. You have to bow them to fit between hub and rim, to get to the hole in the rim. With such short pieces of 12-gauge steel, that took a lot of force.
Rather than ruin the rim liner, I cut a little hole for each nipple I had to access. Replacing the two broken spokes brought the other 34 pretty well into tune. The broken ones were on the chain side. One on the disk side didn't sound tight enough, and I discovered that it was already adjusted as tight as possible. The head was a bit sunken, so I replaced it.
I covered the nipple holes with little squares of 1mm polypropylene. I put duck tape over the squares to keep them in place and give the tube a slick surface. I put the tire back on, but the wheel on the bike, and gave it a spin. It was out of true. With a stick braced against the chain stay, I found a 6" section that was out by 1 or 2 mm.
After I'd tuned the first two replacements, they had relaxed enough for the spokes on the other side of the hub to pull the rim out of line. Retuning the replacements brought the rim into line. The end of the stick dragged evenly against the rim all the way around.
On the head of the third spoke I'd replaced, not even the enamel was damaged. The diameter is 4.6mm. The diameter of the new ones is 4.9mm. That explained why it had sunk somewhat into the countersunk hole in the hub. The problem spokes were defective in head diameter. All three had J bends that had stretched to more than 90 degrees. It makes sense. If the head sinks too deep, the bend is no longer against the other side of the hub. As the angle increases, the pressure on the head focuses on one side. The explains why the heads had popped off on the first two.
If I hadn't periodically tightened loose spokes, they might simple have loosened and let the others carry the load.
I wish Radpower had taken the trouble to answer my inquiry about replacement spokes.