I've been doing this with some old projects: open in CbB, note which plugins don't load, re-open in the last SONAR Platinum (x86), note down 32 bit settings (actually, I usually have the project open in both hosts simultaneously, just am very careful which one I save from!) and listen in isolation then try to recreate in CbB. Tedious but you can get some wins too!
Even Microsoft haven't killed 32 bit completely...Windows Media Player 32 bit is still the default media player in 64 bit Windows 10 (and it's a complete pain trying to get the 63 bit version to be the default in its place...I'm not sure it's even possible in recent Windows 10 releases!).