OAK!Merge will update or add the data to a new record if the field has a pull down menu.  We tested with ACT 12 and OAK!Merge 12.4.2.  Data is updated regardless of whether  or not items are in the pull down menu.   Even if the field was set to "limit to list";  it will be updated.   Consider City and State fields.  They have pull down menus.  If your data has cities or data for the state field that is not in the pull down, it will still be added or updated by OAK!Merge. See screen shots below...

OAK!Merge 12.2 is released 1/10/10.  It now writes to Secondary Contacts. The Pro Version has been out since Oct 2009. The feedback has been great.  The new ACT 12 opportunities and products are working fine. The new PRO version also does ACT! to ACT! merges and appends data to CUSTOM TABLES.

Sample Run_OAKmerge.bat   with Remarks to display as it runs rem batch file to run a merge from a stored profile in OAK!Merge called batch44 "C:\E Tech Systems\ACT\OAK!Merge 12\OakMerge.UI.ACT" batch44 rem "All Done-  log files with results are in C:\E Tech Systems\OAK!Merge 12\Logs" rem rem remove the pause below to run unattended from a scheduler Pause