I guess it’s not clear who is actually doing the update? If it’s for you in a single one-off situation, I’d still recommend the procedure I sent since you don’t need a programmer. If you do have a compatible programmer (nRF91DK or an updated nRF53) they can updated the MFW if you have a Tag Connect (TC2030-CTX-NL)
If it’s something whereas you are having many people or end users facilitate an update, I would suggest looking at the code in the
mfw_update project to see how Nordic facilitates MFW updates through different means. That means you may need to build your own solution or get in touch with Nordic on how they recommend MFW updates over the air or over the wire.
In any case, I typically keep the MFW and SDK static for as long as feasible and only change when it relates to a bug fix. It could introduce many headaches if you update the MFW and it’s not supported by the SDK version you’re using.
This compatibility matrix is handy and a great reference in regards to that: