This gets cited here weekly, usually second-hand, so it is worth setting out what it does and does not establish.
Site reactions are usually technique or temperature rather than the material. Injecting straight from the fridge stings more than injecting at room temperature, alcohol that has not dried carries into the puncture and burns, and re-using the same square inch produces the lump people worry about. Rotate genuinely — different quadrant each week, not different spot in the same quadrant.
Where I think it is weakest: the population was selected and supported in ways a real cohort is not, so I would read the effect size as a ceiling rather than an expectation.
What I am after is whether site reactions are a material issue or a technique issue, and what people changed that actually helped. Not looking for reassurance. Looking for the part I have got wrong.
Note on sourcing:
Figures above are from the primary publication rather than the press summary. If a number here disagrees with one you have, post yours and we will work out which of us is reading a secondary source.