No there is not, that's probably hardcoded. If you repeat at 25 4 times you'll get the equivalent of 100. 
About the video, I believe only by running it on a higher res. I find recording with Fraps to be
pretty darn good, and it's faster than the build-in snapshot render, but it is a comercial $oft.
Yeah, repeating four times sounds absolutely great, how come I didn't think of that?

Jokes aside: I am actually interested in having the single frames, as they are then fed into Adobe Premiere for further processing. Currently, I "only" have three 1920x1080 displays at my disposal, if I would have a fourth, I could get the nVidia Driver into combining the rendering on all for and trick UBOX to render at a much higher resolution, but that does not seem like an elegant solution.
So I guess I will have to wait for US3 and hope it will offer more options to render 4k content and hopefully be able to expand the hardcoded limits.
regards
tuo