In the macro page manual (Text - HALion Macro Page - Steinberg Developer Help) it is said that the read only feature is in Halion 6.1.
This version of Halion 6 does not exist. If you go to the download page the most recent version of Halion is 6.0.15. (HALion 6 | Steinberg).
The most current version of H6 does not have this property.