With SD cards relatively cheap I long thought about, why delete them at all. Just put them into a box after importing the images/when full. So you still have a physical backup.
Because it's a waste of money, space, effort, and nature as well as an unreliable backup that gives you a false sense of security. As well as a good way to leak information.
But yes, keeping the cards for a while and rotating a large pool can be a good approach. When they're in actual reliable ro-at-rest, checksummed, possibly encrypted, offline backup, the cards can be reused. (Always format in device etc.)
I tried to copy some files once. I was unsure about the syntax of "cp" and my sleep deprived brain did neither remember to just try "man cp", nor when I searched via Bing to add "syntax" to the search term "cp".
This lead to a very stern warning, that let me wonder if I'm on a list now...
At least in Germany eye doctors are very happy to prescribe them. It's "only" eye drops, but it is (for laymen) almost impossible to find information if they are also dangerous in this form.
We have an interpreted language in which you can call "subroutines" by name. But you can build the name in you program "on the fly", for example out of data.
It's possible and it's what you should be doing. "sbctl" (https://github.com/Foxboron/sbctl) AFAIK has a reasonable frontend for doing that on Linux (don't know, I did it manually). You have to put the system in "secure boot setup mode" in BIOS/UEFI options before booting, which enables changing the PK (Platform Key) which is used to chain off all the other keys. (Setup mode should be automatically exited when you install a new PK.)
You can keep the Microsoft keys in there if you want to dual boot Windows, you just need to re-sign the keys themselves with your own PK.
That would be a disaster. Or imagine what would happen if you just disabled secure boot, your computer will be infected with viruses and your bank account emptied instantly I reckon