Yes, amongst the already mentioned methods, for the cpan client, you can use distroprefs. You can use that to block a complete author, in your case somewhat like:

$ cat ~/.cpan/prefs/MLEHMANN.yml
---
comment: "use common sense"
match:
    distribution: "^MLEHMANN/"
disabled: 1
[download]

Or you can block all of his modules except for some others:

$ cat ~/.cpan/prefs/MLEHMANN.yml
---
comment: "use common sense"
match:
    distribution: "^MLEHMANN/(?!JSON-XS|Types-Serialiser|Linux-Inotify
+2)"
disabled: 1
[download]

You can also write patches in your own space and allow certain modules only after being patched:

$ cat ~/.cpan/prefs/MLEHMANN.JSON-XS.yml
---
comment: "use common sense"
match:
  distribution: '^MLEHMANN/JSON-XS-3.(0[3-9]|1*)'
patches:
  - "../../patches/JSON-XS.patch"
[download]