Use the following procedure that was recommended by Avid Maestro technical support:
"3Designer can implement emoticons using the following file:
G:\ResourcesRE\Emoticons\Emoticons.xml
By default, this file references a folder containing graphics files provided with 3Designer. You can use your own emoticons by changing the path of the referenced folder, and the names of the files that each Unicode sequence refers.
In the file, emoticons like ":))" should precede ":)", because the first matching emoticon is used; otherwise ":))" will appear as a ":)" graphics with the ")" symbol. Errors may also be caused by the use of the "<" sign. To display emoticons: Select Use Emoticons in the Decoration + tab in 3Designer."
As we were told by the Avid Maestro support team, this works from 3Designer 3.10 and RE 6.7 or later versions.
This solution is intended for emoticons but applies to emojis since what it does is replace sequences of Unicode characters with an image. Based on this we have attached the emoticons.xml file built using the Twitter Emoji taken from https://github.com/twitter/twemoji.
Twemoji v13.0.2 adheres to the Unicode 13.0 spec and supports the Emoji 13.0 spec. The Twemoji library offers support for 3360 emojis, including skin tone and gender modifiers.
Also a zip with the images of this project, which uses the Emoticons.xml file as it should be decompressed in G:\ResourcesRE\Emoticons\Textures for the Render Engine
The images are from the mentioned project and have license CC-BY 4.0.
Bear in mind that emojis will be replaced only in the Render Engine. This is not the case for Maestro where they appear as "squares" characters if the selected font is not supported by the operating system.
A detailed that was not clarified is that the Emoticons.xml is set to replace the characters when the font is Arial
<xml>
<Fonts>
<Font Name="Arial">
In case you use a different Font, you should replace it in Emoticons.xml file with the corresponding font and the same for the emojis replaced.