Ossia staff workaround or another method for drawing instructions

I’m looking for a way to add an Ossia staff, with the staff setup different than the nested instrument.
Picture attached.

In this picture I thought the easiest would be to add an ossia staff of 2 lines and use the line tool to draw inside whatever I need.
This is very common in contemporary music in string instruments for writing quick changes between sul pont. and sul tasto. since a couple decades.

I think the method I mentioned is not possible in Dorico but is there any other way of working around it?
Any help is appreciated.
Screenshot 2020-04-23 at 16.25.07.jpg

You’re right that at the moment this kind of notation is not easily possible in Dorico, though it’s the kind of thing we hope to support in future.

For the time being, you might be able to approximate it by using a two-line percussion kit and the new horizontal lines added in Dorico 3.1.

You can get something pretty close with a couple of horizontal lines and a pedal line. You can increase the width and play around with the retake levels until it looks right.

Thanks both of you for your answers.

JesterMusician, that is the solution I was actually using but I got frustrated because every time I edit something in those bars (notes, dynamics, etc) then the horizontal lines or its inner contents shift around, and I either have to manually go back to engrave mode and put them in place each time, or leave it until later and get use to look at it with the lines being messy.
Is there an option that I’m missing here? perhaps for making those lines stay locked in place?

Thanks again.