After some reviewal, we have fixed some problems, but we still think the expected outcome should be as follows:

        $answerOptionsByScaleId = array(
            0 => array(
                'AO01' => array(
                    'code' => 'AO01',
                    'answer' => 'Option 1, scale 1',
                    'assessment_value' => '0',
                    'scale_id' => '0',
                    'order' => '0'
                ),
                'AO02' => array(
                    'code' => 'AO02',
                    'answer' => 'Option 2, scale 1',
                    'assessment_value' => '0',
                    'scale_id' => '0',
                    'order' => '1'
                ),
                'AO03' => array(
                    'code' => 'AO03',
                    'answer' => 'Option 3, scale 1',
                    'assessment_value' => '0',
                    'scale_id' => '0',
                    'order' => '2'
                )
            ),
            1 => array(
                'AO01' => array(
                    'code' => 'AO01',
                    'answer' => 'Option 1, scale 2',
                    'assessment_value' => '0',
                    'scale_id' => '1',
                    'order' => '3'
                ),
                'AO02' => array(
                    'code' => 'AO02',
                    'answer' => 'Option 2, scale 2',
                    'assessment_value' => '0',
                    'scale_id' => '1',
                    'order' => '4'
                ),
                'AO03' => array(
                    'code' => 'AO03',
                    'answer' => 'Option 3, scale 2',
                    'assessment_value' => '0',
                    'scale_id' => '1',
                    'order' => '5'
                )
            ),
        );

(this is n PHP, not in json)

Thoughts?

https://github.com/LimeSurvey/LimeSurvey/pull/3025

This sounds good. I think using a multidimensional array is probably the savest solution. Does this impact other question types like a array flexible label? This type has just one scale. Will this also result in a 2 dimensional array, or will single scale questions still be a flat array?

Reviewed, have auto test : ready to merge ?

@pixelit array flexible label have only one answer scale (+ one subquestions)

Fix committed to master branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&id=34411

Fixed in Release 5.6.14+230403

@DenisChenu Are you aware of any other question type that has dual scale?

For answers : no i don't think

For Sub-questions : on Array/text and array/number ?

New tests for the gest_question_properties method.
https://github.com/LimeSurvey/LimeSurvey/pull/3049

Fix committed to master branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&id=34594

Fixed in Release 6.0.6+230508