Sorting Autocomplete Selections | WordPress.org

The following PHP will add JavaScript to post.php and post-new.php screens to sort entries in the field insurances alphabetically in human-readable numeric order on load and any time the values are changed:

<?php

/**
 * @see 
 * @see 
 * @see 
 */
add_action(
	'admin_print_footer_scripts',
	function(){
		global $pagenow;
		if ( 'post.php' !== $pagenow && 'post-new.php' !== $pagenow ) {
			return;
		}
?>
<script>
document.addEventListener('DOMContentLoaded', function() {
	if ('undefined' === typeof window.PodsDFV) {
		return;
	}

	// Observe changes in the field values.
	const observer = new MutationObserver(function(mutationList, observer) {
		mutationList.forEach(mutation => {
			if (mutation.type === 'childList') {
				// If an input element is added or removed, sort.
				for (const node of [...mutation.addedNodes, ...mutation.removedNodes]) {
					if (node.nodeName === 'INPUT' && node.name.startsWith('pods_meta_insurances')) {
						update_insurances_order();
						return;
					}
				}
			} else if (mutation.type === 'attributes' && mutation.attributeName === 'value') {
				// If an input element has its value modified, sort.
				if (mutation.target.nodeName === 'INPUT' && mutation.target.name.startsWith('pods_meta_insurances')) {
					update_insurances_order();
					return;
				}
			}
		});
	});

	function start_observing() {
		// .pods-form-ui-row-name-insurances corresponds to relationship field with ID "insurances".
		const parentElement = document.querySelector('.pods-form-ui-row-name-insurances .pods-field-wrapper');

		observer.observe(parentElement, {
			attributes: true,
			childList: true,
			subtree: true
		});
	}

	function update_insurances_order() {
		const allFieldValuesAndConfigsOnScreen = window.PodsDFV.getFieldValues();
		allFieldValuesAndConfigsOnScreen.forEach(function(fieldSet) {
			if (
				// pods_meta_insurances corresponds to relationship field with ID "insurances".
				'undefined' === typeof fieldSet.fieldValues.pods_meta_insurances ||
				0 === fieldSet.fieldValues.pods_meta_insurances.length
			) {
				return;
			}

			observer.disconnect();

			// .pods-form-ui-row-name-insurances corresponds to relationship field with ID "insurances".
			const insurance_options = document.querySelectorAll('.pods-form-ui-row-name-insurances .pods-dfv-pick-full-select__value-container > span');
			let insurance_titles = [];

			fieldSet.fieldValues.pods_meta_insurances.forEach(function(id, index) {
				insurance_titles.push({
					'id': id,
					'title': insurance_options[index].textContent.trim()
				});
			});

			const collator = new Intl.Collator('en-US', {
				numeric: true
			});
			insurance_titles.sort(function(a, b) {
				return collator.compare(a.title, b.title);
			});

			let sorted_insurance_ids = [];
			insurance_titles.forEach(function(obj) {
				sorted_insurance_ids.push(obj.id);
			});

			// pods_meta_insurances corresponds to relationship field with ID "insurances".
			window.PodsDFV.setFieldValue(fieldSet.pod, fieldSet.itemId, 'pods_meta_insurances', sorted_insurance_ids);

			start_observing();
		});
	}

	update_insurances_order();
	start_observing()
});
</script>
<?php
	},
	1000
);

@pdclark, I did some testing and this appears to do exactly what I need. Thank you so much! You are a wizard!