Maybe it was suggested before but let me lay it out again here because why not right?
I don't know what's holding our devs back from completing their damage types (i guess it's about balance and wanting to promote variety in weapon choice?). And while at it, maybe they should also consider doing the same to other weapons?
If it's a bad idea feel free to enlighten me :)
You already pointed out why. For Blasters it was good to complete them as they are the "standard" guns. But all weapons in all damage types would greatly reduce variety. I also didn't like that Shadow Autoguns/Pulsars/Magnuses were released, because of this:
Before: "I can't use my Blitz on slimes, let's try out a different weapon like an Umbra Driver"
After: "I can't use my Blitz on slimes, let's craft its shadow equivalent"