Choice Type with help texts per option

ChoiceTypeWithAttr.php

<?php

namespace App\Form;

use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
use Symfony\Component\Form\FormInterface;
use Symfony\Component\Form\FormView;
use Symfony\Component\OptionsResolver\OptionsResolver;

class ChoiceTypeWithAttr extends ChoiceType
{
    public function configureOptions(OptionsResolver $resolver)
    {
        parent::configureOptions($resolver);

        $resolver->setDefined(['choice_help_labels']);
        $resolver->setAllowedTypes('choice_help_labels', 'array');
    }

    public function finishView(FormView $view, FormInterface $form, array $options)
    {
        parent::finishView($view, $form, $options); 

        foreach ($view->children as $child) {
            $child->vars['help'] = $options['choice_help_labels'][$child->vars['value']] ?? [];
        }
    }
}

custom_bootstrap_5.twig.html

{% extends 'bootstrap_5_horizontal_layout.html.twig' %}

{%- block choice_widget_expanded -%}
    <div {{ block('widget_container_attributes') }}>
        {%- for child in form %}
            {{- form_widget(child, {
                parent_label_class: label_attr.class|default(''),
                translation_domain: choice_translation_domain,
                valid: valid,
            }) -}}
            {% if child.vars.help is defined %}
                <div class="form-text">{{ child.vars.help }}</div>
            {% endif %}
        {% endfor -%}
    </div>
{%- endblock choice_widget_expanded -%}

myformtype.php

namespace App\Form;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
use Symfony\Component\Form\Extension\Core\Type\SubmitType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;

class MyFormType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options): void
    {
        $builder
            ->add('roles', ChoiceTypeWithAttr::class, [
                'choices' => [ 
                  'Label for foo' => 'foo',
                  'Label for bar' => 'bar',
                  'Label for baz' => 'baz',
                ],
                'choice_help_labels' => [
                  'foo' => 'Helptext for foo',
                  'bar' => 'Another helptext, but this is for bar',
                  'baz' => 'Final help text for baz',
                ],
                'multiple' => true,
                'expanded' => true,
            ]);
        ....
    }