here my tests are:
When the custom emoticon has a 1-character code: (for example: ?
If I set the filter "sup" -> "What's up?" all works fine.
If I set the filter "sup?" -> "What's up?":
- While typing "sup?", messenger replaces the ? by the CE and Plus doesn't apply the filter when I send the message.
- If before sending the message, I click Ctrl + Z (undo), messenger changes back the CE by its just-typed code, "?". Then I click send and Plus applies the filter and "What's up·" followed by the CE is sent.
When the custom emoticon has a 2-or-more-characters code: (for example: ??
Either with the filter "sup" -> "What's up??" or "sup??" -> "What's up??" it works well. With the second filter, messenger changes the ?? by the CE before sending it, but Plus recognices it and applies the filter.
Sumarizing: What you have to do, is change the code for the CE to something with at least 2 characters... and use a filter like "sup?" -> What's up??" or just "sup" -> What's up??".
With further tests, I've discovered this:
CEs which code has only 1 character don't work with the features of Plus. ie: Commands, tags, filters, ... and, in general, any feature that implies that Plus has to modify the message in any way. Once the message is sent, the CE is lost and when you recall the message using Ctrl + Up Arrow, the code (letter) for the CE you used isn't there.
However, if before sending the message, you can undo * the change letter -> picture of the emoticon that messenger makes, in that case, Plus works well.
* -> If the CE is the last letter of the message, you can just do Ctrl + Z, or, if it's in the middle of the text, write it after typing the message and do Ctrl + Z.
So Plus doesn't seem to "like" 1-character custom emoticons. it's a bug, imo. Let's hope Patchou notices this thread
* Choli wonders if this has something to do with that the filters of Plus has to be at least 2 characters long 
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