The problem is that the font-weight is not propagating properly into the display. In rotEc.svg for "E1"the font-weight=bold from <text> is not being overridden by anything in the <tspan>, so the characters are bold, for "E2" there is a font-weight=normal in the <tspan> so the characters are normal weight. However, in both instances the font information at the top of the display shows "normal". The text and font tool has the same issue.
The problem is that the font-weight is not propagating properly into the display. In rotEc.svg for "E1"the font-weight=bold from <text> is not being overridden by anything in the <tspan>, so the characters are bold, for "E2" there is a font-weight=normal in the <tspan> so the characters are normal weight. However, in both instances the font information at the top of the display shows "normal". The text and font tool has the same issue.