thank you for your contributionā¦
to improve the extension, you might want to consider using helper or download blocks for the 2 scale modes, see again my suggestion for your other extension hereā¦ see also this example Need help to adding helper or drop down blocks in extension - #5 by Taifun - Extension Development - MIT App Inventor Community
also the AddValue method uses the parameter vā¦ a more user friendly name for v would be valueā¦
Taifun