no probs.
dont get me wrong, it can be put in as the photos above, i wouldnt do it that way though.
i use the std breather on my rs, although ive made it so it can be taken apart and cleaned now, but i run it to a breather filter, i havent put a bottle in to act as a catch tank, but once i start work on the rebuild again i will be.

i wouldnt vent anything to air though, as the system does suck in some air on idle, and the FRST has a valve on the oultlet to air box which stops boost pressure being forced into the intake system when you take ya foot off the gas and you get a rush back, other wose known as chatter

i dunno if this picture will help but its taken from a ford tech book i have on the frst, well, its a service book tbh, and is for the differences between the xr2i and frst