Support custom embedded images (icons) within messages.
There are dozens of requests to add additional emojis, and this is especially relevant concerning e.g. flags of countries or languages or to represent the LGBTIQ+ community. However, this is not up to Telegram to implement those as they are defined by the Unicode standard, which issued a statement a while back to not take in suggestions for any kind of flags anymore (and generally emoji suggestions first undergo a very long process until they are finally standardized).
In order to work around that, I propose to utilize the "MessageEntity" type (https://core.telegram.org/type/MessageEntity) to support custom embedded images within messages. A possible implementation on the technical side could extend the MessageEntity with a new type "messageEntityIcon", which then could be followed by an attribute containing base64 image data. The images are either restricted in size, or get scaled down to the size of regular emojis on the target platform. As for the clients, the contextual menu already used for formatting could allow inserting an image through the standard image editor.
Once uploaded icons can simply be copy pasted, or might end up in another custom menu like GIFs or stickers, or even on the standard emoji screen as a dedicated section.
As concerning problematic content, they might just be reported like regular messages are already are.
As concerning accessibility, for instance screenreaders, an alt-text might be provided with another attribute.
It would not solve embedded pictures to make posts more blog like. With read more feature it would make Telegram blog like platform. Then only good access from web and it’s facebook like 😉