with the 40+ you shouldnt have to overline the rod. That line is more of a line and a half type line.
I use rio outbound floaters 95% of the time. Always want to be able to fish poppers.
Where did you get the information that the 40+ is a line and a half? I'm not sure what that means, but I think you mean that it is a 1/2 line weight heavier than its rating . . .
With shooting heads, it's generally accepted to go up at least one line weight category, if not two line weights (particularly for fast action rods). If the 40+ is a 1/2 line weight heavier than its rating, then it wouldn't be unheard of at all to upline by one. I have the 40+ in a couple of line weights, and I am considering uplining one line weight on certain of my rods to get the line to shoot better . . .
The 40+ and the Outbound are similar but different lines. Both are integrated shooting head lines. I find the running line on the Outbound is much thinner than on the 40+ and, although I haven't measured them on a scale, it seems the equivalent Outbound head may be a little heavier than the 40+; either one of these items allows the Outbound to 'shoot' better than the 40+.
The upside to the thicker running line of the 40+ is that it is easier to handle (i.e. stripping in). The (relatively) thicker running line (at least in the intermediate head and floating heads) allows the 40+ to be cast more like a traditional fly lines, as well. In my opinion, the Outbound is a better shooting line, but I think the 40+ is a better 'handling' line. Kind of the classical debate of using Amnesia/mono type running line or fly line running line for shooting heads; one gets better distance, while the other is better handling. Ya picks your poison . . .