I see, it is a single job you want to send to tapes as Incremental which include everything. In your policy the incrementals are the current Mon-Thur retention and then weekly/monthly/yearly full. You want to put everything to tape or do you plan to use repositories as well for faster recovery times when the data is offiste?
Our GFS policies assume full only due to the nature of the retention schedule, a yearly backup with incremental would require all the incremental's for the year to be available to keep consistency with that one single backup so a full makes more sense as it is self contained. In your case you actually have two jobs to run, one being the incremental Mon-Thurs and one the active-full to tape and GFS. This is the way Veeam would treat it.
Going back to my initial thought with a twist the first job is the backup job to a repository and secondary Target to tape with incremental's only and no GFS Mon-Thur, then second job is full-only to using GFS policy Friday only.
You say you get clashes with two jobs, if you backup to tape from a backup job you are backing up the files already backed up on the repository and not your live production data, you could schedule the second job during the day without impacting your live environment avoiding the clash.
Maybe it's just a different way to think about doing the job but you can achieve your result.