@TaxGuyBill  With a full step-up, it is likely that amending will save the client more tax than what you would charge for your fees, so the client will want to amend.

Sheer conjecture.  Let's say it's a $20,000 step-up.  (I know, it could be $2,000 or $200,000, but we don't know.)  So over a year and a half (I'm assuming she died in mid-2017) it's about $1,000 more depreciation.  In a 22% tax bracket, that's a $220 difference.  Maybe a small amount of state tax, also.  You do amended returns for less than $100 a year?  I'll send you some clients.  

On the other hand, maybe the AGI is over $150K and we're just adjusting the carryover losses.  Does that require amended returns, I wonder?

The real advantage here is to reset the accumulated depreciation.