We are having the same issue as yoyo and reported the problem to lacerte that we are not being able to specially allocate the k-3 numbers.  Most of our partnerships have special allocations so this is just not acceptable.  Below is Lacertes response:

Dear 

You contacted a member of our support staff regarding an unexpected behavior experienced in Intuit Lacerte. We promised to send you periodic updates on case number 1575980896 to keep you informed. Below is the latest update:

2021 PAR US Schedule K-3 Partner Overrides for Part II Section 1 Missing

This unexpected behavior has been determined to be working as designed. For more information related to this investigation, click Here

No further updates are scheduled for this Investigation. This will be our final communication for case number 1575980896

We thank you for your patience.
Intuit Customer Success