SAF:

Lacerte can print a note on page two of the K-1 noting that Box L is now tax capital basis as the regulations require.

The current problem is; if Schedule L and Schedule M-2 remain on some other basis such as GAAP, Sec 704(b) book Lacerte will not allow different amounts in Box L, K-1.

IRS instructions require beginning capital to be "tax capital basis" as we know, however any change to Box l will force a change to Schedule L and M-2. This is a flaw in the program, Intuit engineering refuses to address this until enough users revolt. 

To comply with the new regulation, you have to force an adjustment in the balance sheet and M-2