Bulk file renaming using keywords in Lightroom

what I am doing (trying to do) is bulk renaming files using keywords previously generated,

By @ionut22773150lqo6

But why? Seriously, it's not a great idea.

Apart from being difficult to achieve, it's not good practice and sooner or later it will come back to bite you. Have a read through https://www.dpbestflow.org/file-management/file-naming .

Even if LrC was able to carefully stay just under the operating system limit, for overall file naming including folder path, you would then have a file that would unpredictably refuse to save into a recipient's computer, if you sent it to them - depending on how deep within the folder structure they were trying to put that, and also on how many characters long each of their own folder names were. That problem would lie in wait for all future usage of the image. Perhaps you would make a problem for yourself even, when it came to making backups. Or, in later reorganising your own images. Or, you may find yourself unable to export some of your images - if you want to include their filename along with other info, such as capture date, or even if the folder path you are trying to export into, has itself got too many characters.

Pragmatically: do you really commit to re-rename every image, forever, any time you change your mind or have a new requirement, as to what keywords are assigned? Or if you edit some keyword's spelling? Can you guarantee never to forget, or otherwise fail, to do so?

Also logically: say a virtual copy is to be given a different set of keywords than its respective master copy - it must accordingly DIFFER from whatever keywords may reflect in the source filename.

Exports whether from a master copy or a virtual copy automatically inherit all of its keywording as well as EXIF etc, in the form of standard image metadata, and IMO that is the best form to have this info. Consumers of an image cannot easily scan through a very lengthy filename to see whether it includes a particular word or not - they may not even be able to do so, practically speaking, depending on the context in which they are viewing that filename.

I believe you are striking a Windows limitation (not Lightroom). I have read this elsewhere-

"Under the Windows file naming system the total name cannot or path exceed 259 characters. This includes the folder path, file name and file extension."

Nothing I know of, in LrC, will compress the keywords for a filename/rename.

Why is saving keywords to file metadata not acceptable?