Putting this up for argument rather than for agreement. I have read it twice and I am still not certain what it supports.
Steady state is the thing most people miss. The terminal half-life is about a week, so every dose step takes four to five weeks to fully express itself. Judging a step at day ten is judging the ascent, not the plateau, and it is the single commonest reason people escalate before they needed to.
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.
The narrow version of the question is whether anyone has held at a sub-maximal dose long term and kept the result, or whether the maintenance data only exists at 2.4mg. Happy to be told the question itself is 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.