I slightly reworked the PR and I'm planning to move forward with it, after some polishing.

How the options are currently named and what they are trying to express:

• hash_rename_assets: Patterns of filenames of assets that will be renamed by inserting a hash to the filename
• hash_append_assets: Patterns of filenames of assets that will always be linked by appending a query parameter with a hash

These names are really bad. Does anyone have ideas?

cache_busting_[with]_hash/query? 🤷

If we consider that we add the hash to either the filename or the url, here are a few names that come in mind:

• use_hash_filename
• use_hash_url

• add_hash_filenames
• add_hash_urls

• hash_add_filenames
• hash_add_urls

or simply

• hashed_filenames
• hashed_urls

Not sure which one I prefer yet...

I like Ultrabug's last 2 options, however I fear that using url could be a bit confusing because users might input urls...

Since it's a list of patterns of paths to extras it might be something like:
extras_hashed_via_rename and (extras_hashed_via_query or extras_hashed_via_param) 😄
or make it shorter removing the extras_ part,
hashed_via_rename and (hashed_via_query or hashed_via_param)
or even shorter
hash_via_rename and (hash_via_query or hash_via_param)

But then could it be confused for hashing the files themselves? 😵
Anyways, just my 2 cents ✌️

How about the following?

• hash_filenames
• hash_urls