1. What SCL have you settled into?
2. How many clears are you doing?
3. Have you played it optimally for placement?
SCL9, single hit on each node to the end, do the 3 boss battles, work back down the nodes redoing each one until I get the red ISO or the tick, sometimes skipping a node if it's evil, stopping entirely when I get the CP, or have all the red ISO from the nodes, whichever is later.
Placement is too much effort on top of everything else.
I am a 4* VIP player starved for resources (LTs, CP, ISO, RISO). My focus is progression only (which is also my current approach to PvE and PvP). With normal PvE, I do SCL9 unless it is a tile mover heavy event with a boosted list that doesn't fit my roster or boosts only low tier toons. So far I've only done SCL8 in Support Circuit because there hasn't been a great boosted list for my roster yet.
Similar to some others above, my clearing approach is a single hit on each node to the end, do the 3 boss battles, then work back down the nodes redoing each one 3x more (total of 4 clears each) along the way. By ignoring placement, it doesn't matter when I start or finish and I don't have to do all the clears in one sitting, which has made the event more bearable. Since I don't care about placement, I can also pick whatever slice best fits my schedule and join whenever I feel like it.
You may ask--why do the hardest nodes first if I don't care about placement? It comes down to health/health pack regeneration. I'm more likely to use health packs on the harder nodes and don't want to spend HP buying more, so by hitting the harder nodes first, if I do run low, I can switch to the easy nodes then stop playing long enough for the health packs to regen.