Just wanted to share my take on DO/CA farmer this league:

https://pastebin.com/TuEpxFbq

Defense:

Determination, Grace, Defiance banner, conditional crit immunity (60% from watcher's eye, another 40% if the enemy is cursed) , temporal chains (via skitterbots) , molten shell (cast on damage taken) , Divine flesh, Elusive from withering step , 4.2 k life at lvl 97

Offense:

lvl 30 Vaal caustic arrow , ~495k DO farming dps(at 15 withered stacks), Despair (via skitterbots) , Malevolence , Profane Bloom.

Misc:

5% of life on kill recovery , rampage, onslaught from flask , curse on hit on gloves for longer Profane Bloom explosions

Summary:

A very comfy farmer, can run Sanctum just fine (except for no-hit runs and You might have to survive 1 red storm , depending on the mods. Use topaz flask for Lycia's final form). Will die occasionally in juiced T16 maps. The bow and 21 Vaal caustic arrow gem are roughly half of the 30 div budget, so one can start this build at like 10 div budget at the cost of some damage.