Worth mentioning that most MJ-872s ought to come with the uprated charger- the one that comes with cheap Magicshines is a bit temperamental but I’ve not seen any reports of issues with the newer one.
Where are you going to put it? The Inton strikes me as a bar light because of its size, but the beam seems more suited to helmet use. I’d want to see one in person to be sure of that but the head unit’s certainly larger and heavier than the 872 and Fluxient.
The 872 works very well in either but with your P7 as well, I’d suggest you try it as a helmet light, with the P7 as a spare/infill.
The Fluxient looks like very much the same sort of thing as the 872- I wonder if it’s different at all inside? Oh, Torchy’s comparison shots are all with an 872 fitted with the daft opaque lens, which is now superceded with a clear one that doesn’t stifle the output.
I think I’d go for the Fluxient personally… Not that there’s anything wrong with the 872, it’s stunningly good tbh, but the Fluxient comes with a higher capacity battery, which would allow more use of full beam, and the better warranty from Torchy. (don’t be too concerned about run time though- with most current lights the lower power modes are still very powerful)