Obsidian is a good tool for the brainstorming. A useful plugin would allow to mark an idea or some topic with a mouse, to press a shortcut, to fill in an email address in a pop-up template and to send a marked text to the email recipient to convert the idea into task.
Some project management software, like OpenProject can fetch and parse inbound e-mails to convert them into tasks. In such a manner, it would be possible to build a bridge between ideas and their realization in the form of a good structured project.