Hi Roberto, I don't believe it's possible to set the order via API.
It may be possible to find the Task pane specific entries in the Windows Registry and modify those to suit.
is must be possible, ours is always as first. It could be coincidence, but GUID starts with 11xx therefore it is on the top of registry keys list HKEY_CURRENT_USER\Software\SolidWorks\AddInsStartup
Mine randomly alternates between first and last!
I tried to change the GUID with your, but the order is carried out only in the register at HKEY_CURRENT_USER\Software\SolidWorks\AddInsStartup
and in the menu additions SolidWorks.
In taskpane the order remains the same, as in the image that I had attached.
Have you any ideas?