Suggestion mode only works with specific blocks at this moment. Check this for compatibility and limitation of the suggestion feature.
You can use Suggestion Mode to manage the editorial process of content creation and collaboratively navigate through editorial workflows and troubleshooting in one location.
Any edits to posts or pages are highlighted to accept, reject and collaborate as needed when combined with mentions and notifications. Mentions and notifications generate automated alerts sent via email and Slack—depending on the Administrator’s settings (Admin Dashboard > Multicollab > Settings).
Teams can easily track any text modified, deleted, or added throughout your editorial workflow directly within WordPress or the above-mentioned alerts.