The one reason I have not entirely switched to SL is because of this. I need StreamElements for the store for my stream. I am a low end streamer and lost pretty much all my audience when I was sick for a month and a half (some sort of cold super virus.)
The amount of items I would like to sell is way way more than the overlay would allow for, and it would get far too long a list if it could. Also, I prefer to use that for what it is meant for, little perks for currency and gambling using the currency, since very few, if any people watching me actually use the games I have in scripts, despite a !games command. (I honestly don't know how to fix this, I ended my account with another company that took way too much of the income small streamers obtain from donations, rewards etc, and much less from high end streamers, mostly because everyone just ignored the random encounters, etc.