I'm on a Mac keyboard and I would prefer to have special characters available similar or the same to how they are accessed in OS X/macOS. Here is a similar question for Windows. E.g., alt+e+e → é and alt+c → ç without any GNOME Compose key funkiness.
Is there any tool that provides this function? Or is this something that should be changed in some possibly outdated Mac keyboard layout settings? If the latter, how would I resolve conflicts with existing alt+letter shortcuts (both in identifying the conflict and working around them), e.g., would the alt+letter shortcut do both the shortcut and produce the special character? Are there any patent conflicts or intellectual property reasons to not duplicate this function?