The purpose of flouroflux seems to be to make it last longer and therefore more convenient than regular nutrients. The nutrients from flouroflux recipe however turns flouroflux into a multiplier on the number of regular nutrients produced, meaning nettles effectively become a massive nutrient source which I don't think is intended. Below calculations assume we use a biochamber without modules, so 50% productivity.

Regular bioflux turns into 12 nutrients each which are worth 2 MJ. 8 bioflux and 2 nettles can be turned into 3 flouroflux, which is 64x3=192 MJ of nutrients, same as the 8x12x2=192 MJ from the bioflux. If we turn it into nutrients however, we get 60 (40x1.5) each. 60x3x2=360 MJ of nutrients which is almost twice as much. The closest to the original fuel value would instead be 21 nutrients, meaning after productivity we get 21x1.5x2=63 MJ of nutrients per flouroflux.

If nettles themselves are not supposed to give any energy then 21 nutrients would be appropriate instead of the current 40, or maybe a little bit higher since they do contain some. The recipe also currently allows for productivity modules, which grants an even higher increase since we get an extra step in production. If we are to keep the flouroflux as only a way to store and more conveniently use nutrients, then 21 nutrients and no productivity would be appropriate. Another alternative would be to increase the nutrient value of flouroflux itself, maybe we could say it makes the nutrients more bio-available and therefore more efficient. Right now, it feels inefficient to use flouroflux in machines directly when you could nearly double the number of nutrients through a single biochamber.

Ah i see your point, the original intent was to ensure that if you based your nutrient system around fluroflux rather than bioflux, you'd still need nutrients to make the pentapod eggs, so I mimicked the nutrient conversion kind of recipe - I remember doing some math at the time to make it equivalent to the bioflux amount of the fluroflux, but things might of changes during an update, or perhaps I wanted to give it a small bonus. But you're right, its not 'ideal' to have the fluroflux outperformed in a raw sense by how much nutrients it gives you. But then again - the problem with nutrients typically isn't that you have too much of them , its their short lifespan. Its honestly not the worse thing in the world you if want to power things from nutrients derived from fluroflux - you still have the additional complexity of the initial processing, and the issue of breaking it down rather than using fluroflux raw. Perhaps I will get around to balancing out the nutrient amount but I don't know if it is particularly hurtful to the balance of the mod just yet. Maybe I will do some further play-testing myself too. I have been doing a 100x cost science vanilla run which has taken up a lot of my modding fun time haha. Thanks for the feedback!