Now go back and read what the program says in your screenshot.
do you mean that "program already tells it works with 1080/1080ti"?
If so, yes i can read.
since P104 is also with GDDR5X i just tried and give feedback.
Also in this article they said it is possible.
http://1stminingrig.com/gtx-1080-and-gtx-1080ti-hashrate-increase-up-to-55-mh-s-on-ethereum-ethashIt is thought that the tool changes RRD & FAW values (timings). Some users allegedly have made the same tweaks to p102 and p104 mining edition cards through other means. Moreover, there is a chance that the two mentioned card models wont work with this specific tool.
The P104 is essentially a 1080 with improved GDDRx5 timings (for mining). The app basically does what the manufacturers did for the P104 out of the box. From the screenshot you posted it seems you already have 40 Mh on the GPU. 1080 owners say they got at most 38-39 with the Enlargement Pill- so you are doing better already.