WOW!
Sometimes you find mekoros in the strangest places when you weren’t even looking for them.
Last night I was reading through the hakdamahs and haskamahs for the Kav Hayashar, a combination halacha-mussar-kabbalah sefer. The original had Lashon Hakodesh on the top and “Loshon Ashkenaz” at the bottom. This sefer has an enthusiastic haskama by the Pri Megadim (The poseik hador of his time- Reb Yaakov Kaminetzky ZT”L said that his test to become the rabbi of Tzitevian in Lithuania was “every line of the Pri Megadim”). This haskama mentions that this sefer is for Talmidei chachamim, laymen, and women (who were able to read the “Lashon Ashkenaz”, as the Pri Megadim calls it.) The other prefaces in the sefer mention that many women continue to learn this sefer even today. This sefer also explains the reasons for mitzvos, and has many direct quotes from the Zohar. Yet, it was muuttar for women to read due to the weakened conditions of Jewry after the Shabsai Tzvi incident. So if this sefer is muttar, then the Ramban definitely is.