I really enjoy that this mod addresses the "lack of locations" or "place" problem that factorio has. It's subtle, but widespread. An equivalent problem can exist in real life and even there, I often feel like I can't articulate it well enough. Factorio is a 2d world so it's more clear here - with some landfill and cliff explosives, the world can easily become a homogenous expanse that resembles a blank canvas more than a world. That might be desirable sometimes, but often it ends up making the world feel empty, especially later in the game.

These power crystals add something that even rarer ores don't. A sense of place. Somewhere that is mechanically different from other places. It's a shame that it isn't more popular. There don't seem to be many mods that address this problem so effectively.

That said, I have some suggestions for how it might be improved:

• The "tag new crystals" setting doesn't seem to update properly if it gets changed within a game
• It would be nice if the the crystals didn't generate within a certain distance of spawn - the spawn location has the crashed spaceship and is a respawn point as well so it's already rather significant in terms of being a "place". Beacons also aren't impactful until more machines are unlocked so I think they're mostly a distraction if they happen to generate right on top of the starting ore patches or that general area.
• The distribution area for negative crystals could be colored differently than the others
• The "magicky" aesthetics don't fit the vanilla theme of factorio - perhaps the crystals could be rebranded as technological artifacts similar to the abandoned alien structures shown in recent FFF dev blogs: FFF398, FFF399
• The different tiers are difficult to distinguish from each other - perhaps a larger size difference would help, or they could have slightly different shapes with the stronger crystals being taller, or the smaller versions could be less active and barely lit up or not quite floating above the ground, or just bobbing up and down in a shorter range. If structures are used instead of crystals, they could have red/blue/green colored lights and the more powerful versions could again be more active with more lights or other animated features.
• The core concept could be expanded to include naturally-spawned versions of other entities - artifacts which deliver electrical power to a wide area (more powerful substations) for example. Or perhaps something which generates a substantial amount of power and delivers it to a small area but can't be connected to other power poles. I think there's untapped potential here.

Want to add my opinion on this topic.
I really like this idea. Wondering, why it has like <100 downloads for now. The whole concept of naturally generated areas, which player can use to his advantage, but can't move wherever he wants is really good and i can agree with previous speaker, this i what factorio lacks of.

I think this whole thing can be expanded to apply more interactions besides just "using/avoiding".
What i also think of, player should have the ability to destroy crystals, but that shouldn't be easy. Just removing it like rock or destroing by shooting is out of option. It would be interesting to create some building, which can mine the crystal for several seconds (for example), but it also ulocks somewhere after green/blue packs, takes bunch of energy/lubricant/some other resource. So pllyer still need to ajust it's buildings most of the game, but it's still not some insurmountable obstacle.

Also, Threre would be pretty interesting interaction, if player can "infuse" crystals, changing it's properties. Just some basic idea: any crystal can be destroyed (like on previous part, not just picked up) to get different shards. These shards can be used in tech (independent lab just for shards or their derivatives)/resource/machines, which then can be then used to interact with other crystals. Like, you need 4 "Infusers", place them around crystal, give energy ans specific item. By doing that you can either change the size of affected area, change type of crystal to another (maybe not so good idea, because it kinda breaks the rule of "take what the world gives you"), make it stronger, convert to "Industrial crystal", so it needs energy or conctsnat supply of some resource to give stronger bonuses.
But it still, player can not move crystals, build it's own ones etc.

Maybe some strange interactions, like while destroing/infusing some activities whithin a radius of that process can take the role of catalists: biters being close enough/entity taking damage from fire/fast moving vehicles of any type (build loop of rails to speed up the process/make it less expensive/give extra bonus).
Probably some passive interactions which just happen and deal with it.

I don't know, what is possible and what not, but i think this mod has huge source of interesting features.