In case you missed it (I also didn't see it in the install doc), the new version of Mastodon (v4.2.0)  includes automatic update checking every 30 minutes in the background

#mastodon #fediverse #foss #activitypub #oss #opensource #microblog #updatecheck #ruby #webfinger

https://files.mastodon.social/media_attachments/files/111/127/197/704/075/681/original/e6ad6a1f2dd7dc57.png

https://files.mastodon.social/media_attachments/files/111/127/198/220/658/948/original/971b46f5af62db06.png