@Aurora2017SRL
This extension [actually a plugin] is well over a decade old !
It's also encrypted in the old RBS format.
It's unlikely to get updated.
Luckily the toolbar's code is in the editable RB file...
Find the file in Plugins, it's named Helix-along-curve-tool-0.9.rb
Edit it with a plain text editor [Notepad++ or on MAC bbedit || wrangler ?]
Find the line
helixD_bar.show
and edit it, adding extra text to read
helixD_bar.show if helixD_bar.get_last_state.abs == 1 # TB_VISIBLE/NEVER
Save the changes and restart SketchUp.
Now the toolbar's status will be remembered across sessions - i.e. either visible or off