Can't add gpg keys to template

This is exactly what is expected from upcoming Qubes 4.2. See also: Qubes-specific App Menu · GitHub.

But as you said,

there are quite a few bugs in 4.1, and with few developers, contributions are welcome.

This is not so much a problem of Qubes but a problem of Linux and particularly Fedora running in dom0. Unless a device was targeting Linux (or Qubes), there is typically no documentation of sleep states and no drivers available, so the Linux community is in a very difficult position. If you want to be sure sleep will work for you, consider choosing one of the Community-recommended computers. For example, sleep works fine on my Librem 15.

Looks like a known bug with the update. I’m waiting for a fix, too. Meanwhile this is the recommended update procedure: How to update | Qubes OS.

Thank you for you contribution to spreading Qubes!