I'll often be on call with customer and create a checklist on MacOS Notes on the fly. Then will copy paste that in slack or github for simple tracking.
Mattermost supports threaded replies and Markdown with checklist checkboxes
You can post GitHub/GitLab project updates to a Slack/Mattermost channel with webhooks (and search for and display GH/GL issues with /slash commands); though issue edits and checkbox state changes aren't (yet?) included in the events that channels receive.
I'll often be on call with customer and create a checklist on MacOS Notes on the fly. Then will copy paste that in slack or github for simple tracking.