Hi,
i created a custom field type for WordPress-Tags-like input:
https://github.com/florianbeck/cmb2-field-type-tags

This plugin gives you two CMB2 field types:

1. The tags field acts like WordPress's default tags list.
2. The tags_sortable field acts like WordPress's default tags list as well, but adds sorting.

The Entrys will be saved as single string separated with semicolons.

It would be great, if it will be listed in the 3rd party resources.

Greetings,
Florian