I am going to weigh in here and recommend you look at a cloud-based backup solution like Backblaze. Time Machine can still be used as a layered approach, but Time Machine suffers from a number of flaws. And the war against file service protocols means that anything you try to build yourself will likely break in the future. Here are some concerns:
1: Proximity to production data. Time Machine offers no geographic gap between your live data and your backup. Thus, if you have a localize/regional disaster (fire, floor, lightning, meteor strike, zombie apocalypse, etc.), you run the risk of losing both your production data and your backup. Failing to create a remote backup puts you at risk to lose all your data. The expression, "all eggs in one basket" applies here. If your Mac and the Time Machine are sitting on the same desk and that desk is compromised... well, you get the picture.
2: Reliance on human interaction. Time Machine via an external drive is ripe for failure, particularly with laptops. Desktops are better because they don't move - but see point 1 above for why not to do it. The human (incredibly fallible) must remember to connect and disconnect the drive. This generally results in sporadic compliance. And sporadic compliance means out of compliance. Don't bet on the human as you will lose every time.
3: Capacity. Your 1 TB drive is a fixed capacity. You run the risk of filling the drive after a period of time. You can estimate how long this will take by calculating your average daily rate of change. But why go through the effort when a cloud solution offers unlimited backup capacity.
Years ago, the Library of Congress promoted the concept of the 3-2-1 backup strategy. This proposes that all important data should exist as three copies, on two types of media, and at least one data set stored remotely. Time Machine alone was never compliant with the 2 or the 1 in 3-2-1. Improve the security of your data by embracing the 3-2-1 concept.
Now, this means you can still use Time Machine for a local backup. But augment it with a cloud backup. If you have security concerns, note that Backblaze allows for on-device encryption with your own key before upload to the cloud (don't ever lose your key). But a cloud backup product will resolve point 1, 2, and 3 above. You will have an offsite backup, you will never need to manage anything (backups up automatically), and you will never fill the drive or worry about a failed drive.
Hope this is helpful. Please note, for disclosure, I am a reseller of Backblaze. Research on your own and consider a cloud backup solution that satisfies your data security needs.
