Yoren Chang

Thanks to <a href="https://github.com/WebDevStudios/Taxonomy_Single_Term" rel="nofollow ugc">Taxonomy_Single_Term</a>, a library created by <a href="http://webdevstudios.com/" rel="nofollow ugc">WebDevStudios</a>, it made my work much easier on creating this plugin.
With Categories Metabox Enhanced, you can:
<ul>
<li>Change the built-in Categories metabox/panel to a single term UI, which means replacing the checkboxes with radio buttons or a select drop-down.</li>
<li>Apply the single term UI to other hierarchical taxonomies in the plugin’s Settings page.</li>
<li>Customized the single term UI by setting these options:
<ul>
<li>Priority and position of the metabox placement.</li>
<li>Title of the metabox.</li>
<li>If child-terms should be indenting.</li>
<li>If adding of new terms from the metabox is enable.</li>
</ul>
</li>
</ul>

Categories Metabox Enhanced

Replace the checkboxes with radio buttons or a select drop-down in the built-in Categories metabox and Gutenberg sidebar panel.

010pixel

This plugin will allow you to select custom posts types for which you want to show metabox of template list dropdown menu.
On the front end, this plugin will help to show selected template for the post.
Now you can choose to have different templates for each post just like pages.
Made by <a href="http://www.010pixel.com/" rel="nofollow ugc">010Pixel</a>
<h3>Use</h3>
Before using this plugin, you should have some templates ready to be used.
<ol>
<li>Go to <code>Plugins</code> > <code>Template List Metabox</code>. You will be able to see all the custom post types including <code>Post</code>.</li>
<li>Tick all the checkbox for the post types for which you want to enable template list metabox.</li>
<li>Create a post and choose the template you would like to use.</li>
<li>If you do not want to choose custom template then select <code>Default Template</code>. Choosing <code>Default Template</code> will show content from single.php, single-{$object->post_type}.php, single-{$object->post_type}-{$object->post_name}.php</li>
</ol>
For any query, you can contact me at <a href="http://www.010pixel.com/" rel="nofollow ugc">010 Pixel</a>

Template List Metabox

Template list metabox is to create Metabox for Dropdown List of all available Templates to attach with any Custom Post Types

Categories Metabox Enhanced vs Template List Metabox