Is the curse of knowledge a real effect?
It is worth considering at the outset, that both the extent of knowledge possessed and the ability to teach are subjective and difficult to directly quantify. Therefore, when examining research on the subject, we shouldn't forget that quantification is usually based on indicators loosely correlated to these qualities.
For instance, gauging the extent of knowledge possessed would require some sort of a test (I doubt many academics would subject themselves to the indignity!). Luckily, subject matter knowledge has been tested amongst school teachers, so we have something to go by. Unfortunately, there appears to be a weakly positive correlation, or none at all, between knowledge and ability to teach [1]. Of course, ability to teach is measured by student outcomes, which is also indirect and subject to other factors. A bunch of other markers for knowledge have been  examined in the past, with most exhibiting weak correlations [2].
It is interesting that none of these convey the negative correlation that the 'curse of knowledge' suggests.
Conversely, more recent studies show stronger positive correlations between teaching experience and teacher effectiveness [3,4]. It would then be a fair assumption that the more knowledgeable academics would in general be more senior and therefore have more experience, and thereby be more effective teachers.
Certainly, many of us have personally encountered counter-examples. These encounters probably reinforce the idea of the supposed negative correlation, but are quite clearly a case of confirmation bias. Since the question is about actual research, I think we should just treat the 'curse' as a bit of amusing anectodal folklore.
[1] Byrne, C.J. (1983). Teacher knowledge and teacher effectiveness: A literature review, theoretical analysis and discussion of research strategy. Paper presented at the meeting of the Northwestern Educational Research Association, Ellenville, NY.
[2] Linda Darling-Hammond (2000). Teacher quality and student achievement:
a review of state policy evidence. Volume 8   Number 1, Education Policy Analysis Archives.
[3] https://learningpolicyinstitute.org/product/does-teaching-experience-increase-teacher-effectiveness-review-research
[4] https://www.edweek.org/leadership/new-studies-find-that-for-teachers-experience-really-does-matter/2015/03