There's an extra difficulty with something like video software.
Consider what the expected outcome would be for "isolate from second 1 to second 10". Then the expected outcome for "isolate from frame 1 to frame 10".
What happens with a video at 1fps?
Now we're getting into definitions of "what is 1 second?", and I always reply "a second is a second, regardless of the divisions". Same when syncing audio to video. Straight audio is just a division of sampling rate, so regardless if you record video at 24,25,30, etc, audio recorded at 48kHz is always the same. It only gets confusing when trying to force sync by embedding timecode into the audio or laying the audio to a video format. Now, you're trying to subdivide the audio into video frames, and that's just going to make framerate conversions difficult. My biggest pet peeve with this is all of the MP4 based capture formats where the audio alignment is within +/- frames. I love frame advancing to the clapper in the clapped position, but the audio pop is frame(s) ahead/behind, and sometimes even sub-frames ahead/behind. It's one of the things I miss the most about FCP7. I could option-click the timeline and slip the audio into alignment with the video. Premiere doesn't allow for this, and I refuse to even install FCPX to investigate. I know just make it the audio department's problem ;-) Wow, I just jerked the wheel so hard far left from the actual topic.
It's just a mild thing to get over, and visual tools like this make it very easy to realize the end is exclusive. However, it is not always so easy in video tools unless the next frame to your out is an obvious change.