Greetings, I found there's a simple matter of incompatibility between RR and plutonium energy, which has already been fixed by two mods with two different approaches:
https://mods.factorio.com/mod/RR-PE-PlayNice
and
https://mods.factorio.com/mod/RealisticReactors-PlutoniumEnergy-fuel-fix

They both manage to handle the issue (letting the player use breeder fuel cells in RR breeder reactors) but the problem is that since the ID of the mod has been changed (RR+ being a fork of RR, obviously), the mod loader thinks they're incompatible and asks to download the original version of realistic reactors.
I have, at the moment, simply manually edited the dependency to allow for RRPEPN to work with RR+ and the mod works perfectly with only that one line edit, but I thought that other than writing yet another third mod just for the sake of fixing this, it would be easier to bring this issue to your attention in the hope that it could be fixed upstream in the form of an added compat for realistic reactor and PE for anyone else who might have encountered this issue.

Thank you for your time and thank you for your mod, I'm enjoying it greatly, (although I will say I'm still racking my brain trying to understand how to optimize my setup with reactor rods!)

Thank you for your feedback, Inhralti!

I did not quite understand, what change you propose to do. Could you may be submit a patch here in this thread? I'm not very likely to research it on my own any time soon, but I could include a change, if you provide it.

There is also a couple of other minor changes that needs doing: a minor bug, where a reactor could not be started without a 100% full fuel cell inserted even if it didn't burn down the previous one and making Nuclear Fuel mod an optional dependency.

Well, the mod I'm using at the moment (RRPEPN) is a single line of code

data.raw.reactor["realistic-reactor-breeder"].energy_source.fuel_categories = {"nuclear-breeder"}

and that seems to do the trick, I'm imagining that adding that with a simple if statement for compat

if mods["PlutoniumEnergy"] then
should work, it'd basically add extra compatibility between mods by removing the middleman (or middlemod in this case) and add extra compatibility for the fork. At the moment as I said, I simply added an optional compat to RRPEPN for RR+, and as it is, it's working.

One thing, which is a bit unrelated to the topic which I should most likely open its own discussion about, but since I've been trying out K2, are RR reactors meant to be less powerful than their vanilla counterparts when using them in the mod?

A standard 4 reactor setup in k2 gives something along the ballpark of 1.5 GW, while instead with all rods fully retracted, I struggle to manage to extract anything around 500 MW out of 4 connected reactors running at 950+ C°, to the point they don't even require to be cooled under that load but instead lose heat simply by the sheer stress from the amount of heat exchangers and turbines connected even in a very compact setup with negligible heat loss. I understand that I get a 200% efficiency return on used cells (technically 150-160 % when using K2's formulas), but even with that buff getting 1/3th of the power out of the same setup seems like a straight downgrade, so overall RR reactors seem to perform much worse than vanilla reactors, even when at its most optimal setup. I was wondering if there was something I was missing?
Thank you again for your time.