Sometimes two persons start editing the same text (issue, wiki site or oart of it (h1. section) at the same time) that results in conflicts on save action what is a way too late for such a feedback.
It would be useful to get the status (under work) before you start to edit this text too.

Implementation idea.
This could be triggred by the "edit action" which writes to a table the user id, the ressource id (wikisite or wikisite#ancor, issue or issuesite#ancor) and the start time.
If a new edit action is triggered a new entry is done in a table. If the save or Cancel action is triggered the rable entry id removed.
For every of the ite "crud content actions" triggered the table is checked and all entries with "startime+sessionlifetime<actual time" will be removed.
Then for every view/show action on content the table will be looked up for possible running changes onf this content and if yes, the site rednered will be enriched with this information "site/topic/Section under change" e.g with back ground color or similar.