I know this isn't the best solution to the problem, but it's the only one I've been able to find. It involves material trading.
If you're familiar with the Robigo/Sothis run, this will be a lot easier for you. When I got missions from Robigo I noticed that there were a lot of missions to Sothis with rewards for Exquisite Focus Crystals and other G5 mats. So I experimented and was able to get missions for as many as 15 EFC's. As for myself, I was looking for Military Super Capacitors. So, I went to Velinski Enterprise in the Sothis system, and 15 EFC's equaled 3 MSC's. Not a great trade, but at least I found some, where I couldn't find a single one in an HGE (or rather, I couldn't find any HGE's period), and was able to finish engineering my Power Distributor.
The good news is that running from Robigo Mines, to Sothis A 5, back to Robigo, and then to Velinski takes only about 15 minutes. So, it's better than nothing. If you don't do the Robigo/Sothis run or know how to do it, here's the best video I can provide:
[video=youtube;VYD5WGt97VA]https://www.youtube.com/watch?v=VYD5WGt97VA[/video]
A long process for sure, but IMO, a difficult something is better than an certain nothing. At least until they fix he HGE spawn system.