Reading a thread at stackoverflow (1) made me take a closer look at the nl translations of the Edit menu label: The label of the nl edit menu is translated to "Bewerken" (2) in Firefox, but it looks like it's translated to "Wijzig" in MacOS (checked by switching primary language to Dutch and launching Safari). The OS adds those menuitems automagically to any apps Edit menu, so I believe renaming the menu label to "Wijzig" would make both menuitems appear in the nl version of Firefox. (1) https://stackoverflow.com/questions/18870965/remove-dictation-and-special-characters-menu-options-from-nsmenu (12) https://dxr.mozilla.org/l10n-central/rev/c4aff44c3bc8cc2bcb92cd68b1fa224d905f00fc/nl/browser/chrome/browser/browser.dtd#415
Bug 1478347 Comment 9 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
Reading a thread at stackoverflow (1) made me take a closer look at the nl translations of the Edit menu label: The label of the nl edit menu is translated to "Bewerken" (2) in Firefox, but it looks like it's translated to "Wijzig" in MacOS (checked by switching primary language to Dutch and launching Safari). The OS adds those menuitems automagically to any apps Edit menu, so I believe renaming the menu label to "Wijzig" would make both menuitems appear in the nl version of Firefox. (1) https://stackoverflow.com/questions/18870965/remove-dictation-and-special-characters-menu-options-from-nsmenu (2) https://dxr.mozilla.org/l10n-central/rev/c4aff44c3bc8cc2bcb92cd68b1fa224d905f00fc/nl/browser/chrome/browser/browser.dtd#415