Changing coverage groups?

Currently a second year analyst at a BB up for promotion in the summer. I'm in a fairly niche coverage group (think RE, O&G, mining, etc) but spent some time at a boutique in a generalist M&A role prior to my current firm. I was originally fairly keen about joining this industry group, but over the course of the last two years the appeal has waned (partly due to how niche the industry is - clients prefer those with a "technical" understanding in addition to just finance knowledge).

Obviously it isn't too late to change paths 3 years out of school, but curious to hear from people who have made the switch. A few questions from me, but happy to make this an open discussion.

1) For those who were placed into these niche industries but didn't have the industry background, did you feel that you were lacking vs. your counterparts that did (i.e. someone from an engineering background or studied the industry in school)? More concerned about the mid - senior level; execution as an analyst / associate is a commodity

2) Did a coverage group change impact your career progression (i.e. set back a year or more) despite still working in IB at the same or a comparable firm?

3) Did you find the transition more difficult vs. if you were fresh out of school? (i.e. pidgeonholed or labelled as the "energy" or "real estate" guy)

4) How did you frame your story on the change?

5) Based on anecdotal experience (obviously varies and no right answer here), did you find that this type of move was easier done internally, or externally?