VEAI has some minor bugs with video sources and output options.
Full D1 content (720x480) has a pixel aspect ratio of (8/9) .89 but VEAI (and some other programs too) use 0.91 instead. (Also VEAI calls it a SAR.) (10/11 or 0.91 is for partial D1 which is 704x480).
Image sequence output should technically start with frame number 1 as there isn’t really a frame zero in video work. (VEAI uses frame 0-? which is very strange.)
Since VEAI does not support variable framerates (in terms of maintaining the same rates), it should probably warn if the source file has VFR. (Likewise it should probably warn if the source is interlaced, which it accepts but doesn’t support properly.)