How can I disable the customer's rating/feedback section in the RMA module?

There is no setting in the extension configuration to disable it in the admin panel.

However, you can disable the feedback option enabling some code modifications.

Comment out the code part responsible for the feature in the following file: /app/code/Amasty/Rma/view/frontend/templates/account/returns/view.phtml

<?php if (!$request->getRating() && $status->getState() === \Amasty\Rma\Model\OptionSource\State::RESOLVED) : ?>
<div class="amrma-stars-container">
<div class="rated-message amrma-title" style="display:none">
<?= $block->escapeHtml(__('Thank you for your feedback.')); ?>
</div>
<form method="post" name="amrma-stars-form" action="<?= $block->escapeUrl($block->getRateUrl()); ?>">
<input type="hidden" name="hash" value="<?= $block->escapeHtml($request->getUrlHash()); ?>">
<div class="amrma-rating-block">
<p class="amrma-title"><?= $block->escapeHtml(__('How do you rate the work of a manager?')) ?></p>
<div class="amrma-stars-block review-control-vote">
<?php for ($star = 1; $star < 6; $star++) : ?>
<input type="radio" name="rating" id="rating_<?= (int)$star; ?>"
value="<?= (int)$star; ?>" class="amrma-radio radio" aria-required="true">
<label class="amrma-star rating-<?= (int)$star; ?>" for="rating_<?= (int)$star; ?>"
title="<?= $block->escapeHtml(__('%1 star', (int)$star)); ?>">
<span><?= $block->escapeHtml(__('%1 star', (int)$star)); ?></span>
</label>
<?php endfor; ?>
</div>
</div>
<div class="amrma-feedback-container">
<input type="text" class="amrma-feedback" name="rating_comment"
placeholder="<?= $block->escapeHtml(__('You can also leave a comment.')) ?>" />
<button class="amrma-send" title="<?= $block->escapeHtml(__('Send')) ?>"><?= $block->escapeHtml(__('Send')) ?></button>
</div>
</form>
</div>
<script>
require(['jquery'], function ($) {
$(function () {
$('[name="amrma-stars-form"]').submit(function (e) {
if ($('[name="rating"]:checked').length) {
$.post($(this).attr('action'), $(this).serialize(), function () {
$(this).hide();
$('.rated-message').show();
}.bind(this));
}
e.preventDefault();
});
});
});
</script>
<?php endif; ?>