DaveReidUK
Yes, all talk about rules for IPA are way out of scope in this case.
Not commenting on the actions of the two TWR controllers in this case, but as a controller myself, what I can say, is that one of the things that influence when you commit further traffic info, is when one aircraft reports the other aircraft in sight. Especially when it is the aircraft that have to maneuver to avoid collision and/or find its place in a sequence.
It is also quite probable that the 17R controller told his 17L colleague that the Cirrus had the Metro in sight.
There is however an elephant in the room, and that is that commercial pressure to allow parallell VFR operations on that close RWYs on separate frequencies DO introduce an increased risk compared to having one frequency for both runways.
It clearly works well at MANY airports all the time all over the world, but at some point someone will own the risk.🤐