Modifying SDK. Is that good practice?

[Pawel]

Hello,

Is it a good practice to modify SDK files?

I mean, do you use SDK as integral part of your project and feel free to modify it, or do you try to avoid it and just use API's as it is?

This question is a little bit related to this: devzone.nordicsemi.com/.../

[manymany]

For me it is not a good idea because when you want to update the SDK 12.2 ->12.3 for instance you lose your modifications.