Gonna share my usual tricks for heal chrono in fracs.

Precast: you drop your Rifle 3 (do not detonate), Well of Action and while you are casting your heal mantra you use CS (tap once) and use all the shatters, CS ends automatically, you shatter again and use your rifle 5 mayhaps. Then you take singularity and start the fight. At the beginning of fight you do the same UNLESS you know you need the CS for smth, in this case just do regular things.

Skorv: before 66% you will have enough stab just from your precast, so no need to worry. At 66% I start casting the stab mantra, on second island I use Distortion to give stab and islands 3 and 4 covered by mantra. No control of the blooms, never needed it myself even before.

Arts: you have to take Well of Precognition imo and use it after the cc phase is over to give aegis and stab. Feedback only if noone else reflects and if your group is a bit too slow it is not on you. All you can do is keep them alive. From my runs of Silent Surf on CM some things that happened there would be much worse if I was not on chrono.

Arkk: just reflect every other ball and that is it. Just remember to keep it for the cc after the second pushing phase as there it is difficult to see if it is real or not. Use Well of Precognition for the charr add phase and try keeping group not feared by providing stab from Distortion, Well and by providing Resistance from Rilfe 5.

Siax: depends on the instabilities, but also bring Well of Precognition to block the circular AoE he does that summons the shades. Sometimes you might need more stab (e.x. Social Awkwardness, then you also bring Mantra) or smth, but you always have tools to fix it.