I was thinking on using 2 pieces of wire and four magnets to connect the 10440 batteries to the charger, are there any disadvantages?
Yep, that will work fine. Just make sure not to short anything (obviously).
Charge current of 250mA is around or a touch under 1C. That’s on the high end of acceptable charge rates which beats most chargers for smaller cells. It’s got a strange termination according to the HKJ review. It stops at a relatively high charge current (90mA) which would be an issue of leaving the 10440 cells less than fully charged …except that it checks voltage and charges some more. Differences of opinion on the effect that cheat of the CC/CV preferred charging profile has but it’s not a 10440 specific issue. You might want to check to see if you can find info if the light comes on when it goes “off” at 90mA otherwise using it and pulling cells right away will give you less available capacity.
I charge my 10440 with it. No problems. Just have to use the little adaptor thing. Why the wire?
What little adaptor thing? The max length of the battery bay on th MP2 is only as long as a 16340.