Preserve the text style when switching from Default Text Renderer to Wiki Style Renderer

The wiki renderer is a very nice feature. We have enabled it.
But we have found the problem that some descriptions and comments in old issues now are bad formatted, because some symbols like *,|,... are making them to be used as wiki format. What is wrong. It's true that the new issues have to work with the wiki format, but I think that there should be some way to add some way to preserve the text style when one swith from the Default Text Renderer to the Wiki Renderer. Maybe adding automatically a tag to preserve the text unformatted.