Is it possible to have a nightly 4BL and a weekly 4BK?

I would like to set up the 4D backup so that every night the journal file is backed up to a 4BL file and then weekly the datafile is backed up to a 4BK file.

Is this possible to do using the current 4D v18 capabilities without having a full nightly backup and removing the 6 unwanted 4BK files?

I am aware of the New log file command. I could use that to force a new daily journal file.
Is this my only option?

I think that’s correct, to take advantage of the built-in backup scheduler, perhaps you can interrupt a backup 6 out of 7 times in On Backup Startup.