Personally, I would opt for securing them tightly, or some combination of the two. The data I've seen suggests that unless you are dealing with continuously higher C-rates (like 1C and above or 0.5C if you want to be conservative), cell temperature will be within a few degrees of ambient, in this case a little extra airflow would be (1) not necessary, and (2) probably not that effective.
I think your application and environment is probably important as well.
There is also this bit from the EVE
datasheet @Steve_S uploaded to the resources section:
View attachment 14253
Which seems to imply a substantially greater cycle life if pressure is applied to the cells, but I'm not 100% sure I'm reading that right. I don't own EVE cells so Its not something I've spent much time thinking about, and not something I've noticed in other datasheets.