Plasma Cells that fuel the Portable Fusion Reactor require substantially more advanced and greater quantities of science than the reactor they feed. This is incongruous with a sense of progression and largely makes the PFR obsolete as it is unlocked at roughly the same time as the portable antimatter reactor.

Suggestion: Remove the Deep Space Science costs in both He3-He3 and D-He3 Plasma Cells, Change Energy Science 4 to Energy Science 3 for He3-He3 cells to match the PFR, and reduce the total costs by an order of magnitude on both. The cost for the reactor itself is reasonable at 350 total packs, but the plasma cells are an absurd 12k and 25k respectively. 1200 and 2500 would be far more reasonable.

Using RFP with SpaceExploration and K2 if that matters.
examples: https://imgur.com/a/rTFvZZ3

Additional, tangentially-related suggestion: Move the AI cores and Energy Control Units required on the Matter-Antimatter Fuel Cells to the Empty version, reducing the secondary material cost of refilling empty cells.

Plasma Cells that fuel the Portable Fusion Reactor require substantially more advanced and greater quantities of science than the reactor they feed. This is incongruous with a sense of progression and largely makes the PFR obsolete as it is unlocked at roughly the same time as the portable antimatter reactor.

Suggestion: Remove the Deep Space Science costs in both He3-He3 and D-He3 Plasma Cells, Change Energy Science 4 to Energy Science 3 for He3-He3 cells to match the PFR, and reduce the total costs by an order of magnitude on both. The cost for the reactor itself is reasonable at 350 total packs, but the plasma cells are an absurd 12k and 25k respectively. 1200 and 2500 would be far more reasonable.

I forgot about the portable reactors when I was making the SE patch, so their science/recipe costs are not balanced at all. I'll fix it when I get on my PC.

Additional, tangentially-related suggestion: Move the AI cores and Energy Control Units required on the Matter-Antimatter Fuel Cells to the Empty version, reducing the secondary material cost of refilling empty cells.

...this also wasn't intentional, the antimatter fuel cell's refueling cost should be only the matter+antimatter and nothing else. I'll also fix that when I can.

Fixed in 1.6.6, but the plasma cells no longer have the PFR as a prerequisite, because otherwise SE's postprocess automatically changes the science packs for some reason.

Hot diggity dang. I have mad respect for your dedication to maintaining your mod. Thanks a ton for addressing these comparatively-minor issues, and I completely get that mod interoperability can be a pain sometimes : )