For your part, no need to backup and restore it. Because no SWD interface(development kit(EVK) have) support you to restore it.
So we recommend only normal operations on your part, it is dangerous for you if you want to change the detailed boot loader and FW codes and try self-defined FW in it. if bricked, difficult to restore it and may be you need to back plant for restore again.
We recommend self-define FW testing during developing period on EVK part, on EVK:
- You can backup easily
- restore easily
3.debug FW step by step with ST-Link.
hope clearly for you