I’ve even mimicked a Hint component using HTML DIV tags with inline CSS styling to get a little more customization with text. The screenshot doesn’t really show it, but the colored bars will also change to yellow or red depending on the selected choice.
You can still use emoji. It’s just a single character and can be placed in any text or image attribute in a collection. It doesn’t have to be a custom collection.
It depends how you are using them. Emojis are unicode characters and most (if not all) browsers support them. So essentially, you can use them anywhere you can use text.
In the example that Jeff gave you, I’d imagine that his emojis might be output from an if-then-else column that checks the status. Or they might be the result of a relation + lookup, or maybe even a single value. Whatever the case, I’d be quite confident in saying he would be managing them in the Data Editor. Personally, I don’t think I’d ever add emojis with a set column values action, but you could do that if it worked for your use case. Or you could just paste them directly into component text fields.