Hi Tom,
I have two JVC HD200’s and know them well. I’m 98 percent sure that the analog outs on your HD 100 act the same as the 200.
Component out can be output from the cam as 720p60 or 1080i (user selectable). Yes, your footage is 720p30 but it’s going to come out as 720p60, but it will look exactly like 720p30. If the IO HD can accept 720p30 then great but I think it’s still going to think and want to lock onto the footage as 720p60 because it is in fact 720p60 coming out of the camera.
BTW- nothing wrong with working with 720p30 at 60 fps- just requires a bit more storage and rendering time.
Hope this helps.