Hi Daniel,
I found that the solution doesn't work correctly on incident detail form.
Everything seems to be OK until you try to edit the incident again.
Here are the steps to reproduce the issue:
1. make changes on detail_in.htmpl form as mentioned above (Description field and include the JS)
2. open incident and fill any text in the description field (you don't even need to use html formatting) and save it
3. click on Edit - the description field is blank.
It works fine on detail_alg form, but wasn't able to get it to work on detail_in.
SDM r17.1