Currently, there is no support for changing the size of the nextver column of the base _LT table. There is a system trigger that prevents DDL being performed directly on that table. More importantly however, there is a lot of the internal code and a metadata table that uses that size as the maximum supported size. As a result, changing the size of the base table column would run into other issues. This is a known limitation with how many times a single row can be simultaneously modified, and is being looked at to see what can be done. Do you have a rough estimate of of how many rows are approaching the maximum supported size? How many of these modifications of the rows are due to active vs historical workspaces?