record pipe on off

Hi
opinions valued.

At the mo I have 2 programs

preview: displays a camera, streams a camera
record: displays a camera, streams a camera, records a camera

All works fine, but on switch of preview and record the stream-to-vlc is broken and needs to be reinstated. This ends up being a pain watching the stream.

My idea is to put a tap in front of the record pipe. Would issueing on EOS, waiting for the callback and closing the pipe to end a recording be ok.
Any grand idea I’m missing?

Thanks
James