Yes, it is rather easy — but powerful.

Where to specify the scaling, depends also on your opinion. It can be in EA (for example, as diagram tags), or it can be in eaDocX (diagram right-click, same place where you specify whether to include all elements or not).

I think I prefer the latter one, is this is more close to the document, and you control the GUI for this (instead of having to deal with tags).

While on the subject, perhaps other options like rotating the diagram 90/270 degrees makes sense and is easy to implement?

Regarding the scaling, my intention is to specify max width and height (in cm? or perhaps any other unit that word understands, for example, width = 80% of page width…?), instead of a “scaling factor” as referenced in the article (but, perhaps word also understands scaling factors, so the user can choose whether to enter “12cm” or “80%”, and word understands it. If I look at the dialog in word, you can choose “absolute” and “relative” scaling. For relative you can specify the ‘reference’ (for example, relative to page). For the amount, you can enter every value (just text field), so “12 cm” or “80%” should perhaps all go fine.

It may also be useful to have a checkbox to keep aspect-ratio (which I would normally like), but maybe for other purposes aspect-ratio should not be kept constant.

I do not want to make it too complicated for you with all of these options, but it may be easier to implement them all at once instead of having to expand the functionality in an incremental way.