Larry:
I've got extensive experience with solder skips on both 0603 and SOT23 devices. We also installed an "Omega" vibrating wave on our machine, but it didn't really have an impact on solder skips. The major difference that the omega makes is in top-side wetting and VIA hole fill.
We were able to dramatically reduce skips when we switched over to a VOC-Free flux. You can email me privately to get specific name brands. After the switch, we were able to solder even SOT23's. VOC-Free fluxes are more active because the water carrier allows the activators to ionize more quickly (vs. alcohol-based fluxes). The flux that we chose is known on the market to be more thermally stable so that there's still some remaining-even after the chip wave.
Of course, to Dave F's point, process control is everything. Your Lambda dwell time and contact seem adequate, but if you have a chip wave you should also be getting at least .5 second contact time with the chip wave. Also, most fluxes require at least 200 F top-side temp. before wave contact. You might want to double-check the requirements with your flux vendor, and adjust your profile accordingly.
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