Is this the intended science cost for the mod? There are dozens of incremental techs in the 10k+ range in the tree and this seems to be the largest one at 250k packs required. If so, I'm not sure how anyone is supposed to get there. If not, I guess it may be another mod interacting with this one that is doing that? I haven''t messed with the tech multiplier at pre-game settings or anything like that.

https://imgur.com/a/BZgyTOe

Yes, that's the default. Fusion is supposed to be very hard to research but also very good when you're done researching it. If you don't like the cost, use the tech cost multiplier.