Well, unless it happens to be fixed in an further update to OS X.. which is possible I suppose though I don't expect a fix to be implemented, just for this tiny issue... but it might be if the same fix, fixes other oddities elsewhere... in other apps, if there are indeed any such oddities found or reported that are caused by the same problem.
Other than that small chance...
I don't think it will ever get fixed in terms of an further LP9 update.. as LP9 itself hasn't been updated in over a couple of years and given it is now considered EOL by Apple, I don't believe there will be any further updates in the future. Their focus seems to be purely on LPX these days.
Much the same as the much more serious 'vertical black bar' issue with LP8 and modern OS X versions... will never get fixed..... it's EOL'd too...
So, its just something very minor and in reality, inconsequential to the performance and stability of LP9 ... that we will probably have to just live with...... and I can easily do that.