Fix constraint replacement

Hello

I am having assembly with lots of parts assembled using fix constraint... As far as I know, I can create a csys in part and assemble part within assembly using coincidence constraint using both csys...

This ask for change in part which I am not allowed to do as I am not owner of part being used in my assembly... So, I am creating csys in assembly for each part having fixed constraint nd then using coincidence constraint with csys...

This makes my assembly model tree loaded with extra csys features...

Is it possible to remove fixed constraint without creating extra feature...

Thanks and Regards
Ketan