While the flexibility these abilities offer is already quite powerful, unlike other Planeswalkers that may only activate one ability per turn, you can instead activate two of Urza's abilities during each of your turns
However, depending on the specific meta and strategy of the deck, Surgical Extraction could still see play as a tech choice for targeting blue cards and generating Silver tokens
The staff is totally awesome (especially Josh and Spencer, we love you too Nick )
That said, the synergy that this deck offers is more powerful than the average precon, putting the self-mill version, in my opinion, around a 4.5-5 power level
You lose out on the Treasure but you gain flashback, and with all the draw-two or draw-three card synergies laying around, this black instant from Modern Horizons 3 can do work