Make field help texts initially hidden and expandable (collapsible) by providing a help button/icon attached close to the field's help text. It will be configurable on a per-field basis. Depends on Form element layout.
Contact Storage module will provide storage for Contact messages which are fully-fledged entities in Drupal 8.
This plus core contact module aim to provide functionality equivalent to the base-features of Webform or Entity Form.
The goal is to firm up this functionality in contrib with view to move into core in 8.2.x or later.
The Hierarchial Taxonomy Autocomplete module provides a way to distinctly select terms in a vocabulary when tagging content. For each term that matches by name, the hierarchy for that term is displayed in the drop down.
Note: This module is similar to "Hierarchical Term Reference Autocomplete". I am not sure if this module should be combined with "Hierarchical Term Reference Autocomplete" or if they should remain separate. Their UI and implementation differ. For the purpose of my current project, it made sense to create a standalone module.