Though I don't entirely agree with a customization ability, I am finding that certain templates like Item leave you guessing as to where it will be placed, whether in the side bar or main body. This is one reason why I have implemented using the Vignette primarily and not the prompts/template to its fullest.
While I do not believe the template needs to be adaptable, I utilize a lot of the form-fillable areas to help me get my ideas straightened out. I would appreciate if there were some form of icon or symbol that could inform me that this is going to be in the sidebar or the main body. It is super weird to me that I could fill out essentially six paragraphs of inform only for me to save and view it all sitting in the sidebar.
There actually is a symbol showing if something is placed in the main body or in the sidebar, only it is not used on every template. I don't think it needs to be a toggle to switch between sidebar or main body, there are enough other options for that. But a more consistent use of the symbol would be very much appreciated.
I do not think that the standard templates needs to be adaptable. Because, if you can switch where it is displayed, then you also want to rearrange it and after not too long you are creating custom article templates anyway. In some cases I might even want both like they have on Wikipedia, where a short informative sentence is put in the sidebar and a full explanation is placed in the body. However, the Symbol is already a thing but apparently not implemented in all templates which should be rectified. If you check your Building/Landmark Articles, you see an Indication where the prompt will be placed on the right side inline with the Title.
I disagree with customization options, because it's not needed (you can make stuff yourself) and because there's already ways to build custom article templates for higher ranks. Yet I do agree with showing where what prompt will go, either with an icon, or with a sample article that shows all of them. (I've been surprised by 2 prompt-sections switching order in the actual article, compared to the filled-in data.)
You can rebuild the template however you want using the BBCode and their associated buttons and I've done exactly that by using headers and other things to make the articles appear the way I want with the Vignette. (and for master+ subscription ranks, there's sections like sidebars and the footers) The template prompts are not required to be filled out, and you don't have to use them at all. Most of the BBCode you get access to with the buttons (and ones without buttons) are available to all users. You can check out the Codex article about them as this link! I recall there being a suggestion in the past for something similar for a drag-and-drop arrangement, but there was a really reasonable explanation for why a drag and drop would likely not happen.