Two hands on one staff in long piece
I am working on a harpsichord suite by Christophe Moyreau. Mostly it uses the grand staff, as is normal in keyboard music. However, one section uses only one staff, indicating notes for the right hand with upward-pointing stems and those for the left with downward-pointing ones; see the attachment for a sample. (Note the absence of a bracket at the left of the sample; this is not a grand staff, but two separate systems.)
I set up the piece by specifying harpsichord as the instrument, with treble and bass clefs. Is it possible (perhaps by inserting a section break) to change the instrument to use only one staff for just this portion of the piece and reproduce the original layout?
Perhaps I should ask if this layout is even permitted under modern engraving conventions. The section is long (~100 measures). Using a grand staff would result in all measures being empty in one hand or the other, which I think would look strange.