cross staff beams in choir staff

[Orm Finnendahl]

Hi,

I'm trying to typeset cross staff notes on a 12-staff percussion
system.

Defining the staff systems as "Staff" and the StaffGroup as
"PianoStaff" works well. Trying the same with "ChoirStaff" and the
individual Staff systems as "DrumStaff" results in lots of errors and
the beams and staff lines not drawn at all.

As the brace of the PianoStaff gets really big and bold for 12 staff
systems I'd much prefer using the ChoirStaff for grouping.

Is there a way to achieve that or, as a workaround, can the brace be
removed and the barlines get split between systems using a PianoStaff
group?

--
Orm