MAX is just that, a maximum level. It should be kept anywhere between MAX and MIN. It's more important to make sure it never drops below MIN.

It's also recommended to change the fluid every two years as it deteriorates and is hygroscopic.

I've read that Vgate vLinker FD BT coupled with FORScan Lite for Android is a good combination for diagnostics, i.e. reading data and reading/clearing DTC's. If you want to program, the vLinker FS USB coupled with the free Windows version of FORScan on a laptop. I haven't used any of them though, so...

ASH8, I didn't have any bugs (that I was aware of), but I've updated from OS version 70.00.367 regardless.
Do you have a Mazda Changelog for this most recent version?
Thanks.

I think you can calibrate using an OBD2 scanner and FORScan software. I would ask in the FORScan.org forums, e.g. https://forscan.org/forum/viewtopic.php?t=6381 but you may have leaking injector seals or some other issue. A dealer will be able to tell you if there's an applicable PCM update for your...

I'm not aware of a tidy solution on the CX-3 other than removing the A pillar trim; it's not that difficult to do. There is a Mazda pdf, showing where the clips are, in this thread https://www.cx3forums.co.uk/viewtopic.php?f=11&t=113 and you just have to ensure the cable follows the existing loo...

Don’t turn up with a full tank of fuel; run it down low before you go.

Has someone activated the child safety lock on the door?

Welcome to the forums.

Welcome to the forums.
Check your tyre pressures when cold, and adjust all four to the correct pressure as indicated on the driver's door jamb sticker, then reset TPMS.