How to keep   non-breaking spaces in the visual editor?

I often add   between connecting words so they break down together to a new line in important text. Switching to visual tab then back to text tab removes these. What can I do to keep them and avoid TinyMCE removing them?

I found this but not sure how to apply it to WordPress: https://www.abeautifulsite.net/tinymce-removes-non-breaking-spaces

My ugly solutions would be using a different custom string between words__like__this then later replacing them to   in PHP, before display. Or just typing it on the visual tab, which translates to   but then converting them with PHP.

This seems to do it:

function allow_nbsp_in_tinymce( $mceInit ) {
    $mceInit['entities'] = '160,nbsp,38,amp,60,lt,62,gt';   
    $mceInit['entity_encoding'] = 'named';
    return $mceInit;
}
add_filter( 'tiny_mce_before_init', 'allow_nbsp_in_tinymce' );

Also see: https://www.tinymce.com/docs/configure/content-filtering/#entities

Any improvement suggestions?