Most all cable system use a 15 tp 20 dBmV input at the return amp. housing, not at the IC inside the amd itself. Do not worry about level at return IC, most of today IC can handle 60 dBmV out of 4 return TV channel. You have to worry about the output level at the optical return TX off the NODE.
Here is what I mean for that 15 to 20 dBmV input at the amp. housing.