Maybe buying a burner phone with cash prior to each biz trip to CA can circumvent the commie surveillance.Employees can't deduct unreimbursed travel expenses anymore. If she were to go self employed (only 25.00 in Oklahoma) and have them 1099 her, she could deduct massive amounts of goodies, get paid a california wage, and take home more money. HOWEVER, you'd have the SE tax to contend with so you'd need to have her collect a "wage" of about 35k/year and then a draw of the rest.
If the deductions are pretty big, that's what I'd do. I'd also tell the employer that I'll have more expenses if I do this, so he needs to bump up my pay by 10%.
Now, I do not know anything about how the California communist "You don't live here but we tax you anyway" laws work so they might dip their finger in her pocket for a taste too. You'll have to talk to a CPA about that specifically. I do know that they track your cell phone and if you're in california after you say you moved, they'll tax you for the time you're back in town. Bastards.