Okay, I'll submit something to just add the -makemovie option.
I find it ironic that you call this utility "crazy and hacked up" when you had so much input into creating it. Some of the crazy and hacked up options were created at your request!
Someone else can work out the postprocessing steps to convert mng to avi and chop off the extra frames.
I think you misunderstood me. When I asked for options to be added it was my assumption that you would add them to either your listgen utility or the batch files that do the post processing. Hacking mame is always a bad idea because it makes the whole rig less universal.
We have different philosophies on this.... you have always wanted to do as much as possible inside your custom build. I've always wanted to eliminate the need for custom builds as much as possible.
It's the same reason I switched over to the ahk script for johnny5. When your method was the only way it could be done it was great, but even you can admit that it has severe limitations. When I found a better way it meant that I could update my mame build immediately or even use optimized builds or crazy mame variants and still use the viewer, so I switched. I see a similar opportunity with these new mame core changes.
BuddaMame is a great utility for making movies, but it's not updated fast enough (How can I expect it to? Afterall, you have a life and such

) and it's not the build of mame I'd rather run on my cabinet.
I think the smart thing to do at this point in time (assuming that the mamedevs accept your submission). As to add a final option to buddamame to have it automatically make entries to the ssf.txt file. Then a system could be in place. As new games are added to mame, silver (or whoever's willing to maintain the file) could have the option of checking the start frames manually and releasing and update, or using buddamame to do it for him.
And just as a note, once the mng is converted to avi (tricky, but possible, I've even seen threads on this forum) chopping of extra frames isn't terribly hard.... since everything is in frames, you just need an editor that supports frame-based timelines.
I think you misunderstand my excitement for a more user-friendly way of doing things for a lack of appreciation for what you've been doing to get us this far.