Essentially, I have managed to perform Red Beans installation on the plain dry model objects like planned —

return [
'id' => $user->id,
'email' => $user->email,
'notes' => $user->countOwn('note'),
'links' => [
[
'rel' => 'self',
'uri' => '/users/' . $user->id,
],
],
];

Photo by Michael D Beckwith on Unsplash

And, eureka — based it on internal list properties like $ownNoteList — bear in mind, that not $ownNotesList — i.e. the singular, not plural grammar expression is used internally by Red Beans themselves.

GET /index.php/api/v1/users HTTP/1.1
Host: localhost:2526
{
    "data": [
        {
            "id": "48",
            "email": "21b67482b44dcbd6a95d0fd2fa5d5de0",
            "notes": {
                "42": {
                    "id": "42",
                    "user": null,
                    "data": "{\"text\": \"Lorem ipsum...\"}",
                    "user_id": "48"
                }
            },
            "links": [
                {
                    "rel": "self",
                    "uri": "/users/48"
                }
            ]
        },
        {
            "id": "42",
            "email": "2236eaebf9ad1d3d60266186d71280c1"…