1 thing: as ranger finsih him works better for me.
Friend of mine had a 18 mins solo forge cleared, me and divines had a 23.
q6 daggers speed up toc/tos a bit, since you deal full damage, don't care about the abbysals, as long as you block they can't kill rasti, and they die fast enough.
For defend, just run in the defend spawn, ball them a bit and use a tengu flare, IF you got a good tengu spawn (1 mes 1 nec 1 rit for example) then they kill the group pretty fast and can even fight the next beachsts, so you cna run up in time and catch the running beasts and just solo frontside.
With perfect timing and spawns a ~50 mins run should be possible.
Just sharing my impressions
Btw: ranger is way saver, even if you don't believe me. (but ranger is an extra bit harder at defend).