Hi Miguel,
we will provide Unified Bootloader Framework supporting MagniV, S32K1 and S32K3 devices. The plan was to release it till the end of February, so I hope it will be available in one or two weeks.
Then there's a plan to provide application note similar to AN12218 or AN12323 (these were written for S32K1 devices) later this year but the release date is not known yet. My expectation is rather in H2/2022.
Regards,
Lukas