Well so far I only really noticed 2 differences between the version I'm using and your screenshots:
1 - in your screenshot, a small sized version of the icon associated to the button is visible next to the checkbox: I like that
2 - in your screenshot, there is no grid or visible separation between the column headers: I'm not sure if that's related to Windows 10's theme or due to a change you made, but I must admit I'm not a fan of this
… imho it's better to have a visible indicator of where you should move the mouse cursor if you want to resize the columns, like I circled on the attached screenshot.
From the screenshots only, I didn't figure about the "\n"s not being visible, but since they can't be seen, that wasn't obvious… and I don't think I quite like that either
Since it is a dialog box intended for the user to review/change settings, and they are a part of those settings, I don't see much point in hiding them here. On the contrary, I suppose them not being visible might cause issues in figuring out exactly why a button is displaying as it is.
If you're editing the contents of a specific caption field, do the \n in that very field become visible then? If not, how do you make them visible, so you can know if there are any and where they are?
I'm interested in the "linebreak" feature. Does that make like a horizontal line splitting the space in the interface into different areas, or am I misinterpreting it? If that's what it does, is there a way for the user to add some sort of header/title caption to the different areas?