Hi Laura. The ellipsis must be spaced (see NC Sec.43b) Braille the entire numeral, then one blank cell, then the ellipsis.
As for your curiosity question, I have asked my favorite math teacher who says that repeating decimals should have a horizontal bar (macron) over the repeating numeral/s. He would interpret 2.46... as a rounded number, with additional digits not shown.
Regardless, we braille what we see, following Nemeth Code spacing rules.
Thank you for your question. Lindy Walton (answering for Dorothy)