[2021] What is the new attack mechanic for ignite single target damage?

From the patch notes:

Problem:

Ignite builds don't have a way to focus their damage on bosses, forcing balance to be the same for clear speed damage and boss damage.

Solution:

Change Flame Surge and introduce a new attack-based mechanic to be able to deal much more Burning damage to a targeted enemy.

Specifics:
Flame Surge now creates a burning ground that deals damage equal to a percentage of that ignite if you hit an ignited enemy. Burning Ground can be created every 2 seconds, with a percentage of Ignite Damage on the enemy converted to Burning Ground.

Did they reveal what mechanic this is? Feels important for build planning.