Currently with sub according to simc profile you're performing either rupture or eviscerate roughly every 5 seconds. Rupture accounts for roughly 1/3 of those. An eviscerate every 7.3 seconds means you'll reset the vanish cd in about 20 seconds. If you eviscerate always you'll reset it in about 15 seconds instead, for a 2-set dps increase of roughly 3%. Remember that backstab was buffed, killing hemo weaving, so removing rupture means having to replace a backstab every ~18-20 seconds with a weaker hitting hemo. Rupture does over 60% more damage than eviscerate even assuming 100% FW uptime for eviscerate. So basically you lose damage for every rupture you replace with eviscerate, you lose damage for every backstab you replace with hemo to maintain SV, to go from ~50% to 75% uptime on the 2-set, which is a roughly 3% increase. Based on the T17M simc profile, replacing every rupture with an eviscerate is a cost of ~7% dps, and that's even correcting the eviscerate damage for 100% FW uptime. This is also ignoring the fact that you lose builder damage by replacing backstabs with hemo (but hemo weaving is already assumed on the simc profile because it doesn't consider that in 6.2, backstab is more DPE than hemo).