Hi Pepi
I guess I see this differently to you
When I go to Share I can select a video type, I choose MPEG-4 the profile list shows all Preset Profiles, these are provided by the program installation
The Pen icon is not available, greyed out as we cannot edit any Preset Profiles
When I hit the Plus “+” the existing preset profile is converted to a custom profile, first indication is the name that receives a suffix is added to the name usually “1” (MPEG-4 AVC (1920 x 1080, 25p, 15Mbps) – 1)
A panel opens called “New Profile Options”, maybe the wording should be “New Custom Profile Options”, now I can modify the profile, I usually start by giving it a more meaningful name starting with MY, similar to “MY 1920 x 1080, 25p, 8Mbps”
This Custom Profile is now available at the top of the list, and when selected shows the Pen “Edit Custom Profile” being available, I can now change modify this profile.
If I wished to create another profile I have to start by hitting the plus “+” symbol
The attached image shows the list I see with 4 new custom profiles having been created, the pen is available for these 4 profiles.
The rest of the list are the presets provided by the program, the pen option is not available for these profiles.
We can only edit a profile that we have created and those are Custom Profiles.

- click image for larger view