Tempos seem to not fully fill the output length

[codemann8]

It seems that when tempo is used, the outputted sample length is correct, but the inserted audio doesn't span the entire length of the track, so there is a null section at the end of the track. An example of this occurring is below:

"sub_channels": [
    {
        "pad_start": 22050,
        "file": "music.mp3",
        "sub_tracks": [
            {
                "tempo": 0.88,
                "fade_in": 11025,
                "trim_start": 211388,
                "trim_end": 423326
            }
        ]
    }
]

This one is a bit of an issue and doesn't seem to have any good workaround, other then artificially change the tempo value by trial and error until it stops at the right point, and sub_channel everything and manually throwing in paddings.