Had a player point this out to me: Quicksilver gives +1d to Attune rolls at the cost of taking level 2 harm. Level 2 harm reduces all of your rolls by -1d. So essentially when you take Quicksilver you don’t get any bonus, you just don’t hurt your Attune roll like you hurt everything else.
Is there something I’ve missed here?
You take the harm after the boosted Atttune roll, when the poison kicks in.
Also, being poisoned might not give a penalty to future Attune rolls at all — maybe just to physical actions, depending on how you interpret it.