I can't tell you if it is heretical, but I can give you some information from the chassidic approach that might help you determine how to proceed with the question, and what is needed to find the answer.
The chassidic teachings record that the great Torah leaders of each generation passed on an esoteric tradition. There are many notable events in this tradition but the key ones are Adam Harishon received the secrets of creation from an angel, the Avot were in the chain that received that and added more, then Moshe was taught where it all is in the Torah when he received it at Sinai, and R Shimon Bar Yochai completed it, seeing with a "clear lens" and becoming the final and greatest teacher of the full secrets of the Torah.
After he passed, the knowledge went underground and was only passed among the selected few. We have works from the Geonim and the chassidic masters teach us that they recorded their knowledge in very encrypted form in these works. The subsequent generations enclothed the teachings in philosophy.
This is where I am getting to. The philosophical teachings we have, such as Maimonides, according to the chassidic view, contain within them, secretly, the esoteric teachings. The Rambam "hid and scattered the teachings in pieces throughout his writing", in the form of Aristotelian philosophy, and the mystical tradition he was working from might have even been partial. Many great chassidic Rebbeim, including from Chabad and Ishbitz, who were all great and holy Kabbalists, spilled a lot of ink showing how Rambam's teachings contain these ideas.
R Gershon Henoch writes in his introduction to Beit Yaacov (from chapter 15 there are a few chapters on showing Kabbalah in Rambam) that someone trying to understand the secrets of the Torah from philosophy is akin to someone trying to work backwards from the effect to the cause; a task that is impossible to do completely, if even partially (and uses derivation from argument, which is the exact opposite of Kabbalah, I.e. received wisdom). In the case of philosophy, it's even harder because philosophy, especially the type of Grecian rational philosophies we are talking about, aren't able and aren't even trying to convey anything of the superrational, which is of course where you need to go when you are discussing things that come before intellect! Thus, the only way to learn the secrets of the Torah today is to do so through the teachings of the Zohar, which is the work of Rabbi Shimon Bar Yochai who as we said is the greatest and final teacher of the complete mysteries of Torah. The Zohar is the cause, rather than one of the "effects", going by the above analogy.
R Henoch also points out that the mysteries of creation that are hidden in the teachings of philosophy are muddled with non authentic traditions. In today's day when we have the Zohar and hundreds of works based on it, elucidating the inheritance of Yaacov: the secrets of the Torah, by great holy Chachamim and Rebbeim, including the Arizal, and all the Chassidic Rebbes and great Kabbalists of the last 500 years, there are only very few who seriously still try to unpack the esoteric teachings of the Kabbalah from the enigmatic works of the period when Kabbalah was "underground", including the philosophical works. Still fewer who would allow it, let alone recommend it.
So, according to this traditional approach I have brought, the recommendation would be that if you want to understand the secrets of the Divine, you should start with authentic teachings based on the Zohar, and nowadays there are many options and styles that might suit you, if you are diligent in your search (you said the Neoplatonic ideas help you understand these things and speak to you, which might imply that you've not had such an experience studying the esoteric from traditional Zoharic sources).
It would be very nice if a very learned person will come and just answer your question with a yes/no and neat explanation but I think from what I've laid out here, it seems that there are a number of barriers that might prevent that happening, including the point that rational philosophies are often just not enough and not fully capable of containing complete Divine truths, as well as being a very controversial and dangerous way to approach gaining this Divine knowledge in a "clear lens" way. Philosophy is a tainted and muddled, inadequate esoteric source, and is at best a clothing of encoded information about Divine truth and therefore yes, there are many barriers that may make this question "off topic" in the traditional approach :) As I said, a lot of writing has been written on the Rambam's ways of enclothing Divine esoteric wisdom in philosophy, it might be of interest to you to follow that up, but it is unlikely you'll find the same amount and the same calibre of work done on the Neoplatonic works. You've citied so far only contemporary scholars in a single academic work making that claim. Surely their work would cite some traditional sources who spoke about the Neoplatonic theory? If so, you should go and learn those, of course! Or cite them in the question for us. If there aren't any, then all the more you should consider the recommendations I am laying out here.
I recommend reading his whole introduction to Beit Yaacov, but especially chapters 13 onwards for a few chapters. It is in his work Sha'ar HaEmuna VeYesod HaChassidut, and can be found in English on sefaria. Hatzlacha.