it doesn't. because the yard radius keep going up with more added skills but abyss doesn't pass 12 yard.
so say if you had a weapon with 3+ Enhanced Entropy but maxed out the skill and maxed Abyss, it doesn't do anything.
Same thing as the other skills.
Synergies don’t work with +skills.
Just like you can’t become invincible if you have enough +skills to bring blood oath above 99% redirected dmg, the max is still 43%.
Tooltip errors are common, but this is not a bug.
It would be a bug if it did what you think it should do.