Will non-magnet cases reduce Magsafe efficiency?

[Zak Ray]

Hoping someone with a 12 and magsafe charger can chime in here.

I see a lot of cases out there claiming magsafe "compatibility". Most of them seem to have no magnets in the case, as the official Apple cases do.

I'm sure these cases technically work with magsafe, but is the lack of magnets reducing both charging efficiency and the strength of the puck attachment?

 

[LiemTa]

I tested with a thin 0.3mm case and the strength is significantly weakened

 

[Apple_Robert]

From video reviews I have seen thus far, the MagSafe magnet is not very strong.

 

[Mrrikki]

I tried a thin case and it is not great, far better with a MagSafe approved case.