Jon,
AFAIK those settings are still unchanged from DNN 1 (or even IBuySpy Portal), including help texts. However, in my DNN 4.9.5, there is a difference between both texts:
- Set As Default Settings "...to be used as the default settings when adding new modules"
- Apply To All Modules "...to be applied to all existing modules in the site"
From usability POW, both should be command links instead of check boxes, because they initiate a one time action, not a persisted setting.
Main remaining question: which settings are affected?
For new modules, default affect
- Alignment
- Color
- Border
- IconFile
- Visibility
- ContainerSrc
- DisplayTitle
- DisplayPrint
- DisplaySyndicate
From a look into the source code (ModuleController.vb), AllModules loops through all tabmodules and updates:
- .CacheMethod
- .Alignment
- .Color
- .Border
- .IconFile
- .Visibility (minimized, maximized or hidden)
- .ContainerSrc
- .DisplayTitle (show Title)
- .DisplayPrint
- .DisplaySyndicate
- .IsWebSlice
- .WebSliceTitle
- .WebSliceExpiryDate
- .WebSliceTTL
- .VersionGuid
- .DefaultLanguageGuid
- .LocalizedVersionGuid
- .CultureCode
which makes it obvious, you shouldn't use this option in a site with localized pages (so called "Content Localization") and not on a site using web slices (which either get applied to all other modules or removed from other modules).
IMHO it is a limitation, that there is no indication, which settings are affected - and at least for "apply to all" a more granular control about which properties to apply would be desirable.
ContainerSrc overrides the page default container. Since pages may have different skins and default containers applied, inheriting container from a master on another page (with presumably a different container) sounds not the ideal solution to me. The master/slave hierarchy is already implemented by the segmentation of module settings and tab modules settings, most of the ones listed above shouldn't be inherited from another reference - but maybe from a page (or site navigation branch) default instead of a single one.
Please note, there are no clones. TabModules are references to a single instance, which gets deleted when there is no active reference to the module (at least, this happens in most of the cases). Deleting a module from all pages automatically, doesn't sound reasonable, it requires check whether there are edit permissions for all other pages and users need to remember the master version (main problem imho).