Feature Request: Allow Xtrabackup to backup .json files that are for CONNECT tables that are within the datadir schema dirs

I would like to request that Xtrabackup be able to backup .json files located within schema dirs that are used for CONNECT tables.

Currently, according to the manual:

"It will backup .frm, .MRG, .MYD, .MYI, .TRG, .TRN, .ARM, .ARZ, .CSM, .CSV, .par, and .opt files."

https://www.percona.com/doc/percona-xtrabackup/2.3/how_xtrabackup_works.html

So I would just like to request that .json be added to this list.

I realize that these .json files could be located anywhere, so that is why I think it only fair to back up the ones that are currently in a schema directory that is being backed up, and not ones outside of that.

Thank you for your consideration.

For reference, the CONNECT JSON table type (and subsequent discussion of .json files) is located here:

https://mariadb.com/kb/en/mariadb/connect-json-table-type/