I feel that Creepy Crawly Crystals ought to have more future potential than insulating crystals, as it adjusts the situation of the summoning in a defined way, rather than just asking for new properties in the crystals themselves. And, given that, as problematic as it may be, lightning apparently travels in straight lines in WandRworld, insulation will probably work, as miserable as it is to say so. Also a decent chance to end up with lighter and flawless crystals as a bonus, on account of them being effectively crystallised in a vacuum. Given that the regeneration is drawn from the original summoning magic, it ought to recreate the orignal circumstances too, thus retaining its properties rather than being corrupted over time.
By controlling the summoning process, it ought to be possible to affect other changes to the summoning process, such as overlaying the crystals on lead for make abundant heavy+rigid munitions. Or summoning inside of people, either as a weapon or implants...
Also, the G.M. apparently likes things with names. Even if they are formulaic references.
Creepy= Created from nothingness.
Crawly= Regeneration, they spread out slowly to restore damage.
Crystal= true.
Creepy-Crawly= underwater vacuum= vacuum crystal.
CCC= alliteration.
We just need a +1 from half of these naming traits and it will still blast through all obstacles!