Hullo to you too, EDig!
You may very well be right since she tends to learn new things if required in a project.....like deep diving for "Don't Worry I Am A Ghost" where she did it herself or observed actual court scenes for "Gift for Room 7".
On the other hand it might be just her way of relaxing after a project ends like she went for scuba diving in Phillipines after FBND and got a certificate to the effect. It could be just learning something she is interested in like ballet dancing, skateboarding before the movie last year.
With Shinhye, it is not necessary that she learns only for a project. She is never idle and uses her time well to learn new skills irrespective of wether its sport ( fencing, skateboarding, fishing, bowling, deep diving etc) or arts related ( music, instruments, ballet dancing, emceeing, flower arrangement etc).
These are some of the reason why she is such an interesting person and a good role model.