I was asked to test this again with a newer version. With Gpg4win-5.0.0-beta369 not much has changed, you still can choose "Certify" on the only secret key and the certify window only allows "Cancel". Difference is only that now the "Certify with" line is empty:

Fixed in 1.56.

Fixed in 1.3.2.

We recently noticed problem at a customer site with creating the standard rsa3072 keys. It basically stopped working. A likely cause for this seems to be some anti-malware software slowing down file system calls. In the wake of this we looked again at our file locking strategy and found a few things which are not as they should be. For example the release of the lock before a Close call. Trying to fix this unfortunately caused other problems, thus a couple of fixes are needed.

If a high-contrast mode is enabled then Gpg4win 4.4 (and VSD 3.4) will use the Fusion style which works much better with high contrast than the Windows XP/Vista style with animations that was used previously.

(auto resolved due to the keyword "resolved" in the commit message)

The window was not reenabled on failure

Reading the commit log message in rG6dc3846d7819: sm: Support creation of EdDSA certificates.
I created a file to keygen.

Key-Type: ECDSA
Key-Length: 1024
Key-Grip: 0286DCA85E771F64AB9FD9C89717369524D55471
Key-Usage: sign,encrypt
Hash-Algo: sha384
Serial: random
Name-DN: CN=dummy test nistp384