Occasionally we have a discussion where many images are part of the post, but they’re more for reference vs needing to be seen inline. (And sometimes the inline preview just gets in the way.)
In these cases, having a clickable link to the image would be preferred.
Can you disable or override the thumbnail preview to do so?
The standard way to do that is to make it a link. Since oneboxing requires the link to be on a line by itself, just make sure that image link is not on a line by itself. Like so: