Confused about adjustment to return score.

[PCerles]

https://github.com/PCerles/ctcdecode/blob/master/ctcdecode/src/ctc_beam_search_decoder.cpp#L170

// compute aproximate ctc score as the return score, without affecting the // return order of decoding result. To delete when decoder gets stable.

What is the use of this adjustment to the return score? And what is "unstable" about the decoder? Haven't been able to figure it out. Thanks!