justpassing Intelligent doesn't have the cheaper overnight slot that standard Flux has. But of course is more generous for export. I think the margin between overnight import and peak-rate export is very slightly better on standard Flux than on Intelligent Flux.
Obviously round-trip losses mean just charging overnight and exporting during the day isn't very going to give a huge return, but running high loads overnight (eg charging car / washing machine / dishwasher) then exporting the same power at peak rate might work out slightly better with Flux than Intelligent Flux.
Or If your panels are orientated such that they don't kick in until later in the day, then charging battery overnight on Flux rates to cover morning usage might work out cheaper than importing at Intelligent Flux day rate.
I wonder if Intelligent would work best for the peak production months (lots of excess export), standard Flux for the months when they're closer to balance, and something else (Eco 7 ?) for winter ? But the numbers will all have changed by the spring, so who knows how it will look then.
On the other hand, Intelligent Flux means you can leave Octopus to do all the work, and just reap the benefits. That's got a lot to be said for it.