light at both entrances because of Cheshad (Shabbos 23a)

The gemara says that if a house has two entrances on two different sides, one must light at both entrances because of Cheshad. The Korban Nesanel asks that the halacha is - if it went out, he does not have to relight it (Kahvsa ain zakook lah). But why is this, he should need to relight it because of Cheshad?

The Korban Nesanel answers that the halacha of lighting at both entrances is needed mainly for lighting on Friday night. If a passerby does not see lights at the second entrance, he will suspect the owner of not lighting. But on weekdays, if he does not see lights, he will think that the light probably went out and the owner brought the menorah inside. Therefore the Chachamim made it a requirement to light at both entrances in order to take care of the problem of Cheshad on Friday night.

A simple answer could be that if the light goes out, a person needs to keep his menorah outside to avoid Cheshad, just he does not need to relight it. A problem with this answer is that if it is dark, perhaps people cannot see his menorah, so there would still be Cheshad.

Does anyone know of any other sefer that discusses this question.