Non-Nested Route, where the first path part is parameterized

reacttypescript

hii
i'm trying to create the following routing structure without nesting:
/$id
/$id/edit

i've tried creating a file named

$id_.edit.tsx

$id_.edit.tsx

, but the router seems to ignore the underscore character.
my assumption that it's supposed to work comes from this section of the docs: https://tanstack.com/router/latest/docs/framework/react/routing/routing-concepts#non-nested-routes

is this a bug, or am i doing something wrong?