Specialise now or broaden knowledge?
If you are on a trajectory that will let you quickly complete a doctorate, then I'd suggest that you don't redirect at this time. This depends on your country, of course, and the requirements for a doctorate. In the US, having a broad enough knowledge base that you can pass qualifying exams is a necessity and is also an advantage in that you would be able to teach nearly any undergraduate course after completion. But standards differ.
But you can always broaden your view later if a narrow view is indicated at present. And you can then do so without compromising career goals.
I'll note also, that having insight into one area of math doesn't necessarily translate easily into insight into others, even if they seem quite similar in some ways. I (retired now) had great insight into Real Analysis, but very little into Abstract Algebra. I could fight my way through algebra but it wasn't fun. So, broadening may mean a longer path than you need to travel at this instant. But math can also be synergistic, so ignoring other sub-fields, long term, probably isn't optimal.
If you are well supported in what you are doing now and the end point is reasonably in sight, then it is probably best to keep on keep'n on.  But note that this is mostly just opinion, and others will differ.