I don't have an answer but I really apreciate your attention to detail and the link to the excellent resource on resolution and scanlines.
Can you tell me a bit more about running the widescreen mode on a non widescreen, 4:3, monitor and how you accoplish this?
I have two cabinets running the same basic setup you are describing: 480i CRT via component. I'm focusing on getting the hardware in place while we wait for CoinOps3 on 11.11.11 and plan on resolving some of my video issues & details in the new release.
NOTE: this forum has been in the midst of some very annoying drama. You might want to make sure you save your question on your local computer in case things move get deleted again. I discovered the awesomenss that is CoinOps 2 just as the previous offical forum on 1emulation (or something like that) was imploding.