I've played around a bit with Smith's Threshold cards, here's my thoughts on them and the associated grafts:
Inspirational Blow & Nerve Strike: The OG Threshold cards, used to already be good picks and still are good picks. Extra card draw and Impair are always nice.
Deal: Only needs +1 damage to reach the threshold and gain 2 adrenaline. The adrenaline makes hitting other thresholds easier as well, but it's a pretty common effect on Smith cards already. Fitting for a common card.
Fold 'em: Needs a 6 on a 1-6 damage range to do 3 Wound. Really powerful with proper graft/boon support, the source of Wound for Smith I've been waiting for.
Hold 'em: Needs a 4 on a 2-4 range for 4 Moxie. Incredibly good, that 4 Moxie means 7 extra points of healing and the threshold is easy to hit with some basic damage boosting.
Raise: Needs a 5 on a 2-6 range to reduce a random card's cost by 1. Smith doesn't seem to get that many 0-cost cards, and this basically functions as one if you hit the threshold. Good pick.
The Gamble: Needs a 3 on a 1-3 range, but is Restrained. This one is an actual Gamble, most combos that benefit Threshold don't benefit this one, meaning it's only worth taking if you feel really lucky or get those specific combos.
High Stakes: Gain 2 Defense every time you reach a Threshold. Kinda underwhelming and boring, as many Ability cards are. Only seems worthwhile to me in a very Threshold-heavy deck, though Threshold-heavy decks do seem powerful enough to function well.
Jackpot: Needs a 10 on a 2-4 range to inflict Stun. You'd need 6 power/adrenaline/bonus damage/Threshold reduction to get this to work, but it is the only re-usable way to apply Stun AFAIK. This is a very binary card, it's either great or it's not worth picking at all. It should be clear which it is when the selection comes up. (EDIT: This card works very well with King Hit and Feedback Loop, as do other Threshold cards.)
Mean Streak: Needs a 5 on a 1-5 range to reduce Threshold by 1 for the rest of the turn. Really underwhelming for a Gold card, the only time this is better than getting 1 Adrenaline is in the case of The Gamble. It should either reduce Threshold for the rest of combat, or better yet, have a harder to reach Threshold but also increase Power.
EDIT: Raise in particular has a cool upgrade which lowers its damage range from 2-6 to 1-5 but also improves the Threshold effect from one random cost reduction to TWO random cost reductions. More upgrades that work like this would be appreciated, do you value more consistency or is your build so strong that it can consistently hit the Threshold even with a lowered damage range? It feels good being able to pick the latter.
So far the only Threshold graft is one that lowers the first Threshold of a turn by 1... Or is it? Basically every Graft that increases damage is Threshold support for all Threshold cards bar The Gamble, the most notable ones being Critical Pump and Rugged Wiring, which each give +2 when their conditions are met, going to +3 and even +4 when upgraded. This makes meeting most thresholds very easy. Speed Shot also is a free +1 Adrenaline every turn, which also functionally lowers Thresholds by 1.
The Perfect Shape Perk also deserves mention, that constant +1 Power makes all Thresholds easier to meet.
Overall I do like the Threshold suite of cards, but that's mostly because they reward strategies that were already good: Increasing your damage output. This is in stark contrast with something like Smith's self-destroying/attacking suite of negotiation cards, which tries very hard to reward what would otherwise be a terrible strategy to mixed results.
Speaking of Smith's negotiations, the newly-added Nepotism suite of cards is appreciated. Courtly Nepotism adds a way to make Brags consistent with Buffer or deliver powerful pay-offs with Compel. Meanwhile Degrading Nepotism's Overturn works well in a Bully-style deck of playing as many Hostile cards in a row as possible. I think Notion needs a buff to be worth picking over Overturn, gain 2 Dominance but lose 1 Dominance at the end of the turn gives Smith a way to reverse Dominance decay at the expense of not doing more direct damage with Overturn.
Something else that bears notice is that Adwanatte's social Boon is incredibly powerful when using a Renown-based deck, getting initial Renown as well as Influence means that Brag, Compel and various other Renown cards are instantly live with max damage. I'd say that's powerful to the point that any run focusing on such a deck for Negotiations would be much better off choosing her over Denikus or sparing Theroux. It's also just an outright better version of some already existing social boons, such as those of the Pearlies, Rise Pamphleteers and most notably Mullifree.