2004s BI Add-On in SAPGUI

Hello there...

I was wondering if it is OK to apply both the BW 3.5 Add-On patches to SAPGUi along with the Netweaver 2004s Add-On patches.

The reason I ask is that we are currently on BW 3.5. We are in the process of upgrading our SAPGUI. I really want our GUI to be compatible with NW 2004s since we will be going live with 2004s sometime next year.

I read that the SAPGUI 6.4 is compatible with NW 2004s as of compilation 4, but can I go ahead and add the 2004s Add-On in addition to the BW 3.5 Add-On?

A coworker of mine told me he heard the 2004s Add-On invalidates and/or corrupts the BW 3.5 Add-On. That would not be a good thing for us.