I had a problem with references between assemblies in this post which was answered by Ingvar Magnusson

by advising to set Allow multiple context for parts when editing in assembly option to checked.

My problem is over now but I wonder why this option is set to OFF by default.

Is there any problem that setting it to ON may cause?

Should I leave this option to OFF and turn it ON only in occasions I need it?

I'd like to know if experienced users leave it to OFF or not and why?

Any kind of advice is much appreciated.