EFU File Lists - One strategy - Have I got this right?

[ChrisGreaves]

We each work in different fashions.
T: is my data partition where all my work is held (also a copy of my C:\Users\ folder)
Y: is my nightly backup, a 450 GB USB drive that sleeps in a fire-resistant box.
Z: is my weekly backup, a 900 GB USB drive that sleeps in the fire-resistant box.
Every night I backup T: to Y:
But on Sunday nights, after T: has been backed up to Y:, I backup Y: to Z: (so Z: is a cumulative mass of data) and then Mirror-image T: to Y:.
So Y: is current to within a week of T:.

Now I plan to create an EFU of Y:, and an EFU of Z: on Sunday nights. These two EFUs will be out of date within minutes of being created - as I get back to work creating and deleting files of data.
But as long as i have a normal index of my live data partition T: and a copy of the two EFUs at hand, I ought to be able quickly to locate dear old Crispin.DOT which I could not find yesterday, without mounting a backup drive..

Any file that is created and deleted the same day, before my nightly backup is run is, of course, lost forever.
But once a file has been backed up nightly, it ought always to appear on my nightly Y: back up at least for a week, and ought to appear forever on my cumulative weekly backup Z:.

Does that all make sense so far?

Please, all you super-helpful folks, don't tell me how to ring in/out those two EFUs efficiently; I want to work that out for myself! (If I can)

Thanks, Chris

[void]

Yes, your EFU will go out of date on live volumes.

The EFU files only contain filenames. (not file content)
So if the file is deleted, the content is gone.

Opening an EFU file and performing a filename search is pretty quick and painless.
This filename backup that you're doing looks like a good use for EFU files.

[ChrisGreaves]

This filename backup that you're doing looks like a good use for EFU files.

Thank you, Void, for the confirmation.
Suprisingly, at my age, even knowledge that the file did exist but is now gone can be useful, as it tells the mind that "Yes, I really did produce that file; sad that it's gone, but at least I don't have to spend any more time looking for it".
In the case of my cumulative weekly backup (Z:), the file contents ought always be there, so this use of EFU tells me that it is worth my time getting the drive from its box, mounting it and so on.
Thanks again
Chris