Did i understand this right, that your custom emoticon picker window is not fitting in the screen because you have a lot of big emoticons? How do you see this fixed? A vertical or horizontal scrollbar in that window?
I’m not a programmer, so i cant hint you what and where you have to change in the source, but i think this is the only way to achieve it - change the code. I can only create a request ticket in JIRA SPARK-1050