Does this affect all NSPanel Pro units? Because I don’t see any significant storage usage on mine.
Yes, this affects all NSPanel Pro with v4.0.x firmware. The storage space that is occupied (wasted) varies depending on how many updates have been applied.
Will the upcoming firmware update fix this bug?
v4.0.13 which will be released tomorrow will fix it.
Sorry, the next release is v4.1.0 on November 6th which will include this bugfix.