You stated in answer to a recent question in the name of the ARI z"l that one ought not learn Torah SheBichtav at night. Is there a problem with learning Chumash with Rashi if one gets up in the morning before Alos HaShachar? I like to do Shnayim Mikra V’echad Targum with Rashi early in the morning before I daven because I have no time after davening before going to work.
As in the previous answer you allude to- Chumash with Rashi is permissible at night even according to the custom of the Ari since it includes an element of Torah SheB’al Peh (Shut Yabiya Omer 6, Orach Chayim 30). In any event, if the only time someone can study Shnayim Mikra V'ehad Targum is at night, he should observe that obligation since it is based on the Talmud and brought down in the Shulchan Aruch (Orach Chayim 285) and therefore takes precedence over a Minhag of Mekubbalim. Also, if not studying Torah SheBichtav at night results- not in studying Torah SheBeal Peh- but rather in Bitul Torah, it is of course preferable to study Torah.