In SCR_VONEntryRadio there are methods that presumably determine whether or not radio frequency and power can be set wia 'on screen controls' - [G]+[Scroll]/[R] - but despite modding it to return false it only grayed out controls but player is still able to use them to turn radio on/off and change radio frequency
Here are methods that probably should dictate if on screen controls can be used:
CanBeAdjusted()
CanBeToggled()
Here are affected methods:
AdjustEntry
AdjustEntryModif*
ToggleEntry
Here is a video with controls being grayed out but player still being able to use them despite usage of the code provided in section "Steps To Reproduce"
*AdjustEntryModif this one is not used wia 'on screen actions' but as far as i understand it if CanBeAdjusted() returns false then this also shouldnt be able to adjust radio frequency