I’d like to continue with my topic from my last post on preface articles for journal special sections/collections. So, read that one first if you want to get up to speed. In general, I like them, although let me clarify it a bit by saying that I am ambivalent about pushing the organizers to write a preface. If they choose to do so, then I will fully support them and work with them to make it a good and useful addition to the special section, but I also probably won’t actively encourage the organizers (at least not very much) to write one.
For JGR-Space Physics, there have been 28 special sections/collections since 2002, exactly half of which (14) have a preface/intro/foreword article. Most of these are fairly short (one to three pages) and simply introduce the reason for the special section and provide a brief highlight of most/all of the papers in the special section. A few are longer, providing historical context and a few figures that provide key background for understanding the significance of many the papers. A few others are full review articles of the field.
I have actually been an organizer for two of these 28, and I have written a preface for one and not the other. The one that I wrote (in 2006) was a lengthy review of advancements in the field over the course of the “inner magnetosphere/storms campaign” within the Geospace Environment Modeling program. It was a long preface, actually, being a synthesis of the state of the field. I think I cited several (or even many) of the papers in the special section, but not all of them; the reference list was much longer than that. Now that I think about it, I probably should have cleared my plan with the journal editors before converting it into a review article, but they sent it on to referees and it was eventually published.
Which brings me to my point here and my advice to you: if you are the organizer of a special section and you are wanting to write a preface, then run your idea past the editor with which you are working to get approval for your content and style before setting out to write it. We will most likely agree with whatever you propose, but please keep us informed about your intentions.