Hey! Zed founder here.
We totally agree with this and that's why Zed will switch the keybinding for accepting an edit prediction to `alt-tab` when the cursor is in the leading whitespace of a line. This way you can keep using `tab` for indenting in that situation.
Also, when there's both an edit prediction and and LSP completion, Zed switches the keybinding to `alt-tab` to prevent the conflict with accepting an LSP completion.
Curious to hear what you think!