Hi, thanks for your post.
I wasn't able to download the full research article and would question the ages of the babies selected for the study. Apologies if this was something I have missed.
You already mention that you do not use a massage medium for babies 3 weeks old and given what you already do I wonder if the babies recruited for the study were of a similar age.
I have worked with babies 6 weeks and older and have never had any adverse reactions whilst using sunflower oil. I've never been a fan of olive oil for massage.
Would be interested to hear of your replies from IAIM and the Royal College of Midwives.