Hello, I love that you have added independent emojis to the application, but they are in rasterized format. This causes them to be displayed correctly on all devices inequally. In addition the emojis used are incomplete, many of them have variants for hair and skin color. I leave several suggestions of open source emoji projects that have good support.
If you need help of any kind regarding this, count on me.
But some systems, especially on Android, the oldest ones (like mine for example), do not have full emoji support. They are usually missing enough. That is why it is much appreciated that they come by default and if you want to choose the one of your system then keep the option.
OpenMoji is an interesting proposal, although we are not adapted to it, it seems to promise.
By the way, in recent versions it updated the list of emojis, with tones and in addition expanded. Even the emojis don’t have vector format, therefore it does not scale well on all devices. There is the possibility to value add any of the currently existing?