Hey y'all,
I am going to install a floating engineered floor over concrete slab in a couple of weeks. I have found numerous instances of flatness required for glue down ... 3/16" in 10'
I haven't found if it is the same or different for floating. I'm not sure if it should be the same, less stringent due to the underlayment, or more stringent due to the fact that it can potentially move if it's uneven underneath.

What say you experts? Should I just shut up and make it as level as possible?

Make it as FLAT as possible. We don't use the term 'level"! Always follow manufacterer's installation instructions.

the number 3/16 in 10 feet is the maximum amount of gap. The pad will give some added benefit. I try and go less.