Hello,
just a thought, since this exact problem rises quite often. What do you think about namespacing select2 library to be specific for ACF? I know, that in some cases, that might lead to unnecessary requests, since you might need to load same library more times. But it would solve all those conflicts with various plugins. For example, Yoast SEO does exactly that, they register lib as yoast-seo-select2 and use namespaced calls to lib as well and they would never conflict with other plugins…
Have a nice day, Jakub
