There's no perfect solution but a small floating mobile button in the corner doesn't seem like a big deal if you know most of the time people on your site are g

There's no perfect solution but a small floating mobile button in the corner doesn't seem like a big deal if you know most of the time people on your site are going to be looking for support or sales info. I don't think anyone is advocating a chat window popping up automatically if that's what you're getting at.