Customize automatic naming of item variant codes (omit certain hyphens)

The item variant doctype is really helpful in generating different variants of one item. Unfortunately, ERPnext automatically names the variants in an inconvenient way: It automatically names the Item code based on the Parent Item Code and the Item Attributes and separates them with a hyphen. We have up to 5 different item attributes for one item. The resulting code looks now like:
(where PC is the Parent Item Code and V the different Item Attributes)
So are now 5 hyphens in the final item code which makes the code cumbersome and too long. Ideally we would like to group some variants into one group that are not separated (ommitting certain hyphens) e.g.:

Is that naming convention hard-coded or can it be overwritten somehow using e.g. naming series? In principle, we can rename all items and manually delete the unnecessary hyphens. As we are dealing with potentially hundreds of variants this is not the ideal solution.

I’ve also been searching for a way to customize the automatic item variant naming and haven’t had any luck finding an answer. Has anyone come up with a solution? Can a Document Naming Rule be used in this case?