we are progressing on mythic IL'GYNOTH. It works well, but it would work smoother if there is an addon or weakaura which automatically marks all the ichors.
I'm RL for my raid and in charge of marking/dpsing/calling out ichors. Just have 2 easy binds for 2 marks and call their targets so they can make sure to get their ichor to the eye or ask for grips/typhoons/stuns as needed. Your spellbars should be half empty anyway from the pruning so it's very easy to fit a couple macros for marking. If your RL plays something that's not great for Ichors have someone vocal and with a brain call it.
we had 2 DK's pick a blood, mark with skull and grip in if it was too far away. Also we had all of our healers make a target macro to mark their blood if fixated, freeing up the healer blood with a non skull marker, we just used colors to match our healer, i was diamond since i'm a paladin. It first makes the fight much easier if your healers are kiting less.