0x1C - File Separator
0x1D - Group Separator
0x1E - Record Separator
0x1F - Unit Separator
So I guess 1F would be the "comma" and 1E would be the "newline."
I am pretty sure you shifted the meaning, the decimal separator is part of the atomic data it does not need a control character.
You would use 1F instead of the comma/semicolon/tab and 1E to split lines (record means line just like in SQL).
You could then use 1D to store multiple CSV tables in a single file.
This would confuse most users of csvs they are not programmers they at most use text editors and Excel.