chilihead

Correct. Tags and prefixes would be retained, but it would fall back to default settings, and no formatting.

Yes, to an extent (though note, I haven't tested anything beyond forums, I don't own other apps). All apps that support tags/prefixes should make use of the prefix formatting, and should have the separate prefix dropdown input, no changes needed. They will not have all of the special forum settings (tag mode, default tags/prefix, require, etc). I have plans to extend those settings to all tag-enabled containers, but that will be some time down the road.
The app does not change sorting/filtering options at all. It'll behave the same way it does in a vanilla install. You can click tags and prefixes, and it will take you to a search for all content having that tag/prefix. It will not filter or sort within the forum directly.
This app allows you to override the tag mode on a per-forum basis, so you can have it closed in one place and open in another, and it adds a 'prefixes only' mode. Currently it does not let you change the minimum/maximum tags per forum, but I'll take that into consideration.
Thanks for the feedback.

Advanced Tags & Prefixes
For IPS 4.x
This application enhances IPS Community Suite 4's built-in tag and prefix system. It gives you custom styling and fine-grained control over prefixes, plus new settings, enhancements, and helpful moderation tools. Prefixes are explicitly created through the Admin CP, and can be chosen from a separate prefix dropdown when creating a topic or other prefix-enabled content.
View the Marketplace listing for more info and available features.
Please post any questions, feedback, or support issues here in the support thread.
Go to the Marketplace listing

Unfortunately it's not that simple. Some of the indexes are created with a length based on 3 bytes per char in mind. So when you try and change the collation on those tables you get an error about indexes being too large. To fix it you have to completely delete the indexes on that table, recreate them with a length suitable for 4 bytes per char. Then you can change the collation.
I did it on my board by deleting all the indexes and then changing the collation type in conf_global.php. Then when you run the support tool it spits out the commands for recreating the indexes - even with the correct index lengths for utf8mb4. Not for the faint hearted, it took about 5 hours to recreate.
Info about the index issue: https://mathiasbynens.be/notes/mysql-utf8mb4 
 

I don't understand the fuss. if using utf8_unicode_ci, characters using 4 bytes such as emoji will be refused by the database. if that is an issue, simply update the collation? it's not like it's a different character set, utf8mb4 is a superset of utf8 in mysql, you can go from utf8 to utf8mb4 easily, there's just no going back from utf8mb4 to utf8 without losing data once there is 4-byte data in the database.

No. The scenarios are:
MySQL <= 5.1You cannot use UTF8MB4 at all MySQL >= 5.5UTF8. Certain characters (like certain Emoji) won’t be supported and could cause problems in earlier releases. Therefore the most recent version now warns you about this when you try to include such characters. UTF8MB4: You are free to use any characters. 

This plugin will allow users to set up an automatic reply to personal conversation when they're not available. A new option will be added on Account Settings to users from selected groups. They will be able to enable the auto reply and type the auto reply content. Users with this feature enabled will view a global message warning about the auto reply and will show a link to disable it.
 
Settings (Admin CP):
Groups allowed to use this feature  
Settings (per user on Account Settings):
Enable Auto Reply Auto reply content Note:
Due to the rework on plugin (every new resource has to be done from the scratch to run on  IPS4), a new purchase is required. Thank you for your understanding.  

Here's a small teaser for you.

Still a WIP, subject to change etc.

Sweet! Not ready to buy yet still on version 3.4. Will most likely buy. 

​Sure, I will add Review system for videobox.

yes