i believe this has succeeded if you will confirm this is success as i do see “Good signature”. thx @fepitre. it could have potential for @deeplow to branch this post for helping others look to verify and test 4.1 weekly builds.
mashka@ubuntu:~/Downloads$ gpg --recv-keys 1C8714D640F30457EC953050656946BA873DDEC1
gpg: key 0x656946BA873DDEC1: "fepitre-bot <fepitre-bot@qubes-os.org>" not changed
gpg: Total number processed: 1
gpg: unchanged: 1
mashka@ubuntu:~/Downloads$ gpg -v --verify Qubes-20210410-x86_64.iso.asc Qubes-20210410-x86_64.iso
gpg: Signature made Sat 10 Apr 2021 04:53:28 AM UTC
gpg: using RSA key 1C8714D640F30457EC953050656946BA873DDEC1
gpg: using pgp trust model
gpg: Good signature from "fepitre-bot <fepitre-bot@qubes-os.org>" [unknown]
gpg: WARNING: This key is not certified with a trusted signature!
gpg: There is no indication that the signature belongs to the owner.
Primary key fingerprint: 1C87 14D6 40F3 0457 EC95 3050 6569 46BA 873D DEC1
gpg: binary signature, digest algorithm SHA256, key algorithm rsa4096