Ascendency Skills Support Sockets

I haven’t been able to find an answer to this anywhere online (like with most things PoE 2, lol) so I thought I’d ask here. When do Ascendency specific skills, like the Stormweaver Sorceress’ Elemental Storm, unlock support gem slots? I am level 63 atm and mine has had 3 slots unlocked for quite a while now. I thought the fourth one would unlock at level 60 but it did not and I was curious when it would. I assumed since the campaign ends at around level 70 all of the slots would be open by then but evidently that isn’t the case. I am also assuming it’s tied to level since there is no other way to add more sockets but maybe it’s tied to Ascendency Trial? I really have no idea. Hope someone can shine a light on this!

my infernal hound had 4 slots by around 75ish, not exactly sure where though. could have been 70 and i wouldn't have noticed though

Ok thanks, good to know. I will make sure to keep an eye on it and will update the thread when it unlocks.