We were supported to convert XML chart data range representations
with a hard-coded ';' as the range union operators, but incorrectly
using UI configurable range separators.  This caused charts with
series that consisted of multiple ranges to be imported correctly in
locales where the range separator (which re-uses the function argument
separator) was something other than ';'.

BTW I plan to remove this "always use Calc A1 syntax" restriction in
future versions.