Estimates cause audits, FTB and deceased TP

2015 estimates were used on a C.  The FTB has the return under audit.

2016 not filed.

2017 TP passed away (in February 2017)

The FTB wants returns for 2016 and 2017 but we have little information.

Listing obvious estimates seems right as we don't know the deductions. We have reasonable belief that the TP had business expenses.

Listing obvious estimates would not appeal as I am signing the return.  

The probate process will be finished by end of June. 

Question:

An FTB audit of 2016 would be likely in my opinion. But there will be no money after expenses and taxes.  I think the Executor would be personally liable.  The estate is my client, if I understand correctly.  Do I give advice to the Executor?

EDIT:  I am comfortable with the estimates.  And I am going to add a disclosure statement.

AICPA, SSTS #4

1. When records are missing or precise information about a transaction is not available at the time the return must be filed, a member may prepare a tax return using a taxpayer’s estimates of the missing data.

2. Estimated amounts should not be presented in a manner that provides a misleading impression about the degree of factual accuracy.

3. Specific disclosure that an estimate is used for an item in the return is not generally required; however, such disclosure should be made in unusual circumstances where nondisclosure might mislead the taxing authority regarding the degree of accuracy of the return as a whole. Some examples of unusual circumstances include the following:

   1. A taxpayer has died or is ill at the time the return must be filed.