These IOUS files are entirely unmanageable. About a year ago, after New FamilySearch had a serious impact from additions to these already large files, the programmers placed a cap on the number of files that could be combined. Presently, New FamilySearch imposes an arbitrary 80 file limit on combining files. If a user attempts further combinations after the limit is reached, their is a file error message explaining that the limit has been reached.
The effect of this limit is that many individuals still have unconsolidated duplicate copies floating around in the master file which cannot be combined into one individual. Further, if the uncombined file happens to be the one with "correct" information as opposed to the incorrect combined files, there is no way to show the correct information in all of the files that may be encountered.
Let me give an example. A hypothetical "Sidney Tanner" is shown in New FamilySearch as an ancestor of the user. When the Combined Records button chosen, the results indicates that there are 281 combined records. The effect of this number is that even though a search for duplicate records shows an additional ten or so records, the program will not let these additional records be combined. It is conceivable that all of the 281 combined records have incorrect information and the only one of the ten or so uncombined records has the "correct" information, none the less, the program will not allow a combination of the two records. Although this scenario is extremely unlikely, it does happen.
One of the by products of the introduction of the New FamilySearch program in Utah and Idaho is that many more Legacy Users will be accessing the program. It is certain that additional information will be added and that the number of existing duplicates will increase.
The present Help Menu Item ID 104186 makes the following statement:
Although you will often not be able to do anything because of errors when dealing with Individual records Of Unusual Size, in certain cases you will be able to fix some of the problems until Data Quality and Engineering fix the problems.More later.