Frequency of backup of headers for LUKS1 and LUKS2

Given that I won't add or remove any key from header key slot, or I 
won't re-encrypt (i.e. change the master key), how often do I need to 
backup the LUKS1 and LUKS2 header? Is doing the backup once enough and 
making sure that the backup is not corrupted?

Are there any other situation where one needs to backup the headers of 
LUKS1 and LUKS2 more often?

I was wondering if the contents of header changes in any other way, that 
requires backup, if it affects restore possibility.

Thanks and Regards

Lamy