How inefficient – would it be performance degrading? It would be for a category that lists products – a finite number of say up to 30, with a periodic update every week or so. But the options page could have multiple fields that would need updates passing…
Anyway, it sounds outside the scope of what I want to focus on – I tend to get a result and then try and find another way to see if I can improve it… Currently I retrieve values in a template using the standard php snippets provided by ACF documentation. It works so I should stick with that.
OK so it seems the simplest solution is to put the menu in a template, load the Shortcodes for the 3 menu templates into an ACF Select field and then load the ACF field into the loop using a Shortcode field in Elementor.
A bit more long winded than I wanted but it works.
I found this code to populate a select field with nav menus:
https://whiteleydesigns.com/code/dynamically-populate-acf-select-fields-with-wordpress-menus/
Which it does, but then I don’t have a field to select that choice and represent as a menu.
I guess I could put each of the menu choices (there are only 3 I need) in a template and then display the template using a shortcode populated with an ACF field. A bit more convoluted but should work…