This despite the fact that there was concern about heresy - the reaction against Mendelsohn is a good example. In fact there were some Chasidim who viewed the Malbim as a maskil. While the Reform viewed him as a fanatic reactionary. The Malbim apparently was trying to produce a frum Biblical criticism much as Rav Yisroel Salanter was trying to produce a frum haskala
Dr. Noah Rosenbloom in his biography of the Malbim notes that there were several books in Hebrew - concerning with science - which were published at this time for the frum world. The Malbim apparently took his information from one of them - Sefer HaBris. The author of Sefer haBris clearly was aware of the dangers of publishing discussions of science and he took the precaution of announcing that the work was merely an introduction to Rav Chaim Vital's Shaar HaKedushah - to explain the scientific basis. Of interest he makes no attempt to actually explain any particular verse. As Dr. Rosenbloom points out - if he really was concerned with clarify and explaining Shaar HaKedusha - he would have written it as a commentary rather than as a introduction. In addition he was careful to obtain many haskomas from important rabbis.
My point being that it is not so much the content but the perceived context that influences whether something is perceived as dangerous literature that needs to be banned.
Malbim (Bereishis 1:1) ... This interpretation [which I just quoted] makes sense according to the view of the ancients who says that there exist Spheres on which are fixed all the stars of the Heavens and therefore when it says that G-d created the Heavens it is referring to the Spheres which were created on the first day. And then the sun and the moon and the stars were created on the fourth day and attached to the Spheres that are referred to as the rakia of the Heavens. However it has recently been established that there are no such things as Spheres. Rather [the scientists] have stated that all the heavenly bodies move in their orbits in an atmosphere which is called Ether which fills the entire universe. Therefore if the stars weren't created then nothing of the heavens was created because there is nothing to the Heavens except the heavenly bodies. Furthermore the scientists have recently established that the stars in the Heavens are not composed of a fifth type of matter which is unique to the Heavens as the ancients claimed. The fact is that the heavenly bodies which only reflect light such as the moon are composed of the exact same materials as we find here on our earth....