This appears to be a new shortcut in macOS Sequoia (15.x):
⌃↵ (control + return)
Should be enabled by default, but if it’s not or if you want to change the shortcut:
→ System Settings… → Keyboard → Keyboard Shortcuts… → Keyboard: Show contextual menu
I haven’t tried it in every corner of Scrivener, but where I tried it, it worked as advertised. One less reason to reach for the mouse / trackpad. Without using 3rd-party tools.
(Funnily enough, at the moment it seems to work better / more consistent in Scrivener than in many other programs – including Apple’s own. Kudos! @KB)