Insert (I) bit me again

Future versions of Dorico will provide additional capabilities for Insert mode, as we’ve always intended: the ability to insert not only into the current voice, but into all voices on the current instrument, or even across all instruments; the ability to lengthen the current bar (i.e. changing its effective time signature) rather than push material into following bars (ideal for chant, cadenzas, and so on). We are also planning to add a means of specifying an extent for Insert mode operations, so you can designate a point beyond which you don’t want any music to be shifted, which will then result in any music that would otherwise pass that threshold being deleted.