H.
If Softcam is not visible in Enigma2-GUI, it does not mean that it is not installed. It can be installed. But you used an older IPK-package or one that does not support a specific Enigma2 distribution. The new OpenATV and OpenPLi have the softcam support built-in... so that it contains the file name, as well as the file extension. According to the type of extension, the Enigma2-GUI then identifies, shows, and enables the Softcam to be managed (via the Enigma2 GUI - in MENU). They should be file names such as:
/etc/init.d/softcam.osccam
/etc/init.d/softcam.cccam
/etc/init.d/softcam.ncam
There is a sym-link also created:
/etc/init.d/softcam
...and it points to the currently set and used by the user, one single softcam, out of these several.
Softcam can be updated easily if you get its binary file - according to the type of chipset in your set-top box. Then stop Softcam in Enigma2. Then copy the binary file manually via FTP. And finally, start Softcam again. But even this requires minor IT knowledge.
If you want to keep the updates on feed sources, you have to add another feed source. If you use OpenATV, there is an unofficial feed for it, which you have to install in OpenATV (you can also find it here on the discussion forum).
If you use OpenPLi, they already have a built-in feed with softcams. Hardly, it updates every time you let Enigma2 update. Alternatively, you can update the OpenPLi softcam manually, using the opkg manager, via a Telnet/SSH connection.
/////////// EDIT : (according to your post update)
The symbolic link will not work in this case, because if it refers to a removable USB key, then at the moment of booting Linux, when the USB key is not yet mounted in the system, the non-existent sym-link will be deleted. If I'm not mistaken.
Of course, you can have Oscam configuration files anywhere. But at the moment of starting Oscam, during the boot of the set-top box, the USB must already be mounted in Linux... and I don't know for sure if that will happen. I suppose so. So in theory it should work.
The safest thing is to edit the start link in the shell script in the /etc/init.d folder. Find the appropriate shell script and edit it. Find the executable binary oscam file. Add there an argument for entering a specific configuration path.
-c, --config-dir <dir> | Read configuration files from <dir>
More info: https://wiki.streamboard.tv/wiki/OSCam/en/ShellCommands
For example:
/usr/bin/oscam -c /media/usb/config
Searching of configuration folders after starting Oscam is also built-in. But your choice is not among these folders: Does the location of Oscam's config files depend on the image/hardware being used? -being-use/?postID=618671#post618671