For every map product you use in BaseCamp there will be a key written in HKEY_CURRENT_USER\Software\Garmin\BaseCamp\Setting s\Products. This stores the lat/lon you were viewing as well as rotation, tilt, zoom, etc.
The keys at HKEY_CURRENT_USER\Software\Garmin\SharedSettings\P roducts will only be added if you need to change the projection angle. In the future we may put other cross-application settings in that location but there is nothing else now.
To get the projection angle setting to be applied you need to add a key with the same number as found under BaseCamp settings. The easiest way to figure out which number corresponds to which product is just to delete all the BC Product settings and then start back up seeing which is added as you change maps.
The updated directions are as follows:
Navigate to HKEY_CURRENT_USER\Software\Garmin\SharedSettings\P roducts
Create the new key with the product ID number
Now create a new DWORD key 'ProjectionAngle' under the product key.
Then modify that key to set the projection angle in degrees
Restart BaseCamp for the setting to take effect
Alternatively if the product you would like to tweak is a desktop install (as opposed to a SD card / device product) you can set this value via the Ctrl-Alt-A key sequence in MapSource and BaseCamp will also pick up the setting.