First, since it’s a React, the Automaton will use it when possible (i.e. at the start of the game).
Second, the Grifters that let you discard and draw cards are largely irrelevant to the Automaton, since it has no problems with card cycling. They might be worth using for stats or skills though.
As for the rest, they should have their own exceptions in order to really work well. Exceptions for the cards in the remaining PBE sets are in the works, but until they are ready, I suggest you either don’t include Grifters, use them but ignore the ability, or improvise.
Ok. Thankyou
So, after thinking a bit about grifters in solo, and to keep things simple, here are a couple of house-rules I might include until the official ones are released:
If a grifter searches for a specific type of card (i.e. job, hex, mystical…) and the automaton doesn´t have any on its starting hand, the automaton will use the grifter´s ability.
Butch Deuces (First Peoples)
None (Anarchists)
Howard Aswell (Entrepreneurs)
Funtime Freddy (4th ring (I like the name better than Fearmongers)) Search for the first 2 different hexes
Lew Esquilin (4th ring) Search for the first non-unique mystical or abomination, whichever comes first.
Dr. JT Goodenough (Law Dogs) Search for the first 2 different non-unique Gadget Weapons.
None (Outlaws)
Ol´Howard (drifter) Needs ruling (improvise)
If a grifter only discards and draw cards, don´t use their ability at all, or don´t include them in the Automaton´s deck. (As stated by @zenarchist they are irrelevant)
If a grifter has a specific ability other than the mentioned above, use them as follow:
Sifting Squirrel (First Peoples): Don´t use its ability
Benjamin Washington (Anarchists): Always use the ability if there is at least one dude with upkeep in the Automatons starting posse
Arthur Dingler (Entrepreneurs): Always use the ability, shuffling the cards back to the Automatons deck
None (4th Ring)
Andrew Burton(Law Dogs) Always use the ability, using the target priorities ( rulebook page 41)
The Fixer (Outlaws): Use the ability if the Automaton doesn´t have an action card that starts a job in its starting hand.
Rico Rodegain (drifter): Don´t use its ability.
Travis Moon Exp.1 (drifter) Use it as normal (it´s a react after all)
Hope these rules are simple and good enough, and can help other solo players.
(By the way, how can I write the name of a card so it´s image shows up?)