Boss VF-1 Effect Processor

Hi - I'm new the forum and have a few basic questions about the VF1:

I'm considering buying the VF1, but there doesn't seem to be any way 
to do tap tempo functionality - is this true? I assume I can however 
modify the delay time on the fly with an expression pedal...

A related question - the tempo value global?  Can it be set once and 
effect noy only delay but tremolo and other fx?

Thanks!