The new "Display on Top" feature is a good step for the game but the order of certain effects is still wrong.
We need proper depth sorting instead of band-aid solutions that Nexon keeps throwing out.
I play with 100% skill opacity on the majority of the classes I play and I know others do as well so actually being able to see what we're doing while not having to turn our skills off in certain bosses or on certain characters would be nice.
Outlines didn't work because they're too small which makes them hard to see and certain character's effects still render on top of them making them sometimes useless.
This new option doesn't work for the same reason. The depth order is still incorrect.
Nexon appears to understand this so they added a transparency slider to the new option but that doesn't fix the issue either.
The new option appears to enforce a set depth order of (Drawn Top>Bottom) Player Character > Boss Character > Boss Effects > Player Effects
We however need a more structured order to this. The correct order should be Player Character > Priority Effects > Boss Character > Boss Effects > Player Effects
The reason this needs to exist is because there are certain things in the game that must be interacted with or avoided in order to play the game.
Some effects in the game appear to have been properly set to a priority effect, these things render in the correct order, even on the new setting.
However certain other effects have never rendered in the correct order because Nexon never gave them proper depth priority.
There is also an issue where certain attacks do not respect the order at first but do after they have been "loaded" for lack of a better term.
When first drawn they are drawn in an incorrect order, then fixed after a delay to display in the correct order.
Effects not properly set to "Boss Effects": The following render behind player effects despite the fact that they should not.
Sample of this type. Appears to render behind player effects both with and without the new setting.
Some are worse with the new setting and some aren't noticeable without new setting.
Majority of issues are of this type and are a problem with the game in-general.
Von Bon: Realm Door
Papulatus: Claws
Damien: P2 Blue Balls | Altar + Interact Bar
Slime: Rock Slimes
Lucid: Altar + Interact bar
Will: Phase 1: "Tornado" | Leg/Pillar | Phase 2: Leg/Pillar | Webs | Phase 3: Leg/Pillar
Gloom: Terrible Grasp (Darkness hands)
Verus Hilla: Green/Purple Pillars
Seren: Phase 1: "Banana" Sword Slice | Phase 2: Sunset Fire Pillar/Wall | Sunrise: Walking Deer
Adversary: Phase 1: Shadow Clones | Phase 2: Altar | Floor "Bombs" | Rotating Triple Laser | Bird Wing | Phase 3: Arrow Rain | Red/Blue/Yellow Laser | Small Lasers
Kaling: Phase 1 Dog: Roots
Star: Every single attack as far as I could tell.
Baldrix: Phase 1: Statue Balls | Phase 2: Big Arrow like pattern
Effects that need a new Priority Effects group since the boss can block vision of these.
Example of the problem. Appears behind the boss due to boss being drawn in-front of boss effects.
This is a new bug created by the new depth sorting not respecting previous sorting rules.

Verus Hilla: Strings (These also need an outline for contrast as they are hard to see against skills)
Seren: Phase 2: Midday "Bombs"
Kaling: Phase 1: Chains
Baldrix: Phase 3: In/Out Test
Black Mage: Chains
These lists are incomplete as I cannot test Jupiter and I did not test all the listed bosses fully.
If you know of any more post them here.