Easiest repro: change chat version to TextChatService, change ChatWindowConfiguration to have visible textstroke and then send a message with emoji, then change TextStrokeTransparency configuration again and you will notice the difference.
Repro 2.0: make 2 text labels, one with TextStrokeTransparency 0 and second with 1, add any emoji to both and compare.
Workaround: use UIStroke (it won’t work with rich text)
Expected behavior
Emojis should not render with an outline