I'm not one to look a gift horse in the mouth, but these Illaoi changes.

Illaoi Test of Spirit (E) Cooldown lowered from 20/18/16/14/12 to 16/15/14/13/12 Leap of Faith (R) Cooldown lowered from 120/105/90 to 120/95/70

While the R change is needed and appreciated, I can't say I think the E change is necessary or will fix the biggest underlying issue that prevents Illaoi from seeing high level play - it will, however, make her much more abusing in lanes she already wins. It's a nice compensation buff to encourage Q maxing so she can waveclear better against season 9's more durable minions, but I'd like to propose a different, more ambitious request;

Give Illaoi Unstoppable on Q. Or, at least, shift her displacement immunity from her R to her Q.

My reasoning is simple; there is no champion in the game who immobilizes themselves as much as Illaoi - she already has to lock herself down to small areas of power near tentacle spawns, and then ALSO self-stuns herself on excessively long cast times on 3 different spells. She simultaneously opens herself up to getting CC'd and also has no defense against it. The way her ult works and the way she's reliant on it, she cannot make use of her displacement immunity very often; she can't afford to wait to press R when the best opportunity presents itself, so it is often put to waste.

To add on, in concept she is an anti-engage champion who cannot punish engages with crowd control before the burst, which is unusual for a nesting champion as both Zyra and Heimer will lock you down before bursting you. Illaoi needs a way to outplay opponents in terms of defense, or else she will continue to underperform in higher ranks as anything but a counterpick to Ornn.

I don't think Illaoi needs to have that same quality, but I think the above change would be a great boost to her high elo effectiveness without drastically affecting low elo performances - even though statistically she's quite below average in both ranks.