We are sitting at around 225 pulls, best pull 29%, and as everyone I am starting to lose my mind a bit with this boss. Here are our logs from our last evening on him - this was our most consistent night yet, though we did not push into P3 hardly at all, we were consistently getting to 2nd DPS adds and passing them easier than in the past.
https://www.warcraftlogs.com/reports/q4NfkmpJVFKMv6rw
3 tanks (bear, prot main tanks, blood DK OS 3rd)
4 healers (hpally + shaman are the most important)
We sacrifice the third add player for 1st and 2nd dps adds. Push P1 before third arma. Push to darkness phase after healing adds / arma soak.
I feel like our strategy is sound, we are executing it properly for the most part (occasional dumb knock off deaths and missed swirl), but I would like to see us having active pulls in P3 more frequently to practice safe spot marking.
If anyone can notice anything that we should adjust, I appreciate it. Or, we are just at that point where progress stagnates a bit, until finally it clicks and you kill boss....