Thanks for your reply Pipeline.
Using multi riffs was actually the way I was getting around the situation but I just wondered whether there was a way in RB of arranging more specific custom ends like you can in BIAB video
https://www.youtube.com/watch?v=NF3n9KDcFwI Apparently not.

I have tried unsuccessfully to get a meaningful end using both ticked and unticked 2 bar end boxes and seem to finish up with either an abrupt and unprofessional sounding stop with no gradual decay or even worse, instruments ending at different times or just petering out in chaos shocked

Thank you for your help. Back to the drawing board!

BIAB 2022 PLUSPAK (ext HD), 49PAKs, STYLESPAKs 1 - 6, Win 7 64bit PC, REAPER, Ozone, Adobe Audition CS6, EZ Drummer3 + EZ Keys,Soundcraft MTK22, Behringer X Touch Universal Controller,, SE Gemini/Rode NT2/Neumann/Shure mics