I was a bit skeptical about how well the RV would cope with a dense 1.2mm array of 0402s, but the trial run with resistors looks good....
Likewise - recently I had to build a board for an array of 150x SOD323 diodes, which needed to be as close together as possible. Was a bit nervous designing the board in how close I dared to go, but in the end with a small tweak here and there on the machine it was placing them very well.
Why would you want an array of diodes like that...?
(My job will be LEDs, just tested with R's as they're rather cheaper!)
To be honest I'm not 100% sure, but they are a very specific diode and its part of something that's very high speed, hence why they needed to be as close together as possible.
I do a lot of seemingly 'odd' things for this client, but they really know what they are doing!
I bet it's not that high speed any more as that array must have quite a bit of capacitance and lead inductance.
I think in this case it depends on how you are using it!
I do know a little bit more about it than I'm letting on but I can't really go into more detail because of NDA. The 3 directors of the company I build this for all have doctorates in physics, so I don't pretend to understand everything I build for them!