After you have updated the catalog and configured the download job for the SEP RU10 release in LUA , you notice that only "manager" updates are listed
LUA 2.3.x ; SEP 14.3 RU10
This is by design.
As many of the client's RU9 PVLs are the same for RU10, a decision was made to not duplicate the content and use the existing valid PVLs for RU10.
Therefore, in order to download and distribute content updates for RU10 clients, you'd need to use the RU9 client updates combined to RU10 content.