I would not find Kittle writing in the TDNT as problematic. He seems to present ideas as any respectful of any other scholar. (I'm not sure how much of Kittle is reasonably represented by Peterlag though.) So I would not have a problem considering his contributions -- at least what I know so far.
The TDNT entries by Kittle do not reflect anti-semitism based on an analysis by J. S. Vos per this video (but the video does not note where Vos shares this). As to anti-Trinitarianism, there are interesting abuses by JWs of Kittel's material. see link:
#link trinity-Kittel.htm (www.bible.ca)
I partly was considering the content of the video but also doing AI requests about Kittel and Vos. Some say Kittel was devout Christian and went against the German Rationalism. It could be a useful project or study to assess Kittel's viewpoint, contribution, and concerns. I think in the end it depends whether a person gets their insight from one source or uses many sources plus intuition to understand scripture.