As your Ahrefs plugin currently supports YOAST and RankMath, I am wondering if you could add support for SEOPress as well? SEOPress is not as widely used as YOAST but has a very extensive feature set and those who use it, find it better than YOAST.
This is the field that contains the target keyword that SEOPress users would set: _seopress_analysis_target_kw
Also, adding the link here for the overview of all the fields generated by SEOPress: