Set a negative startTime for comp from script.

I have a script for processing footage where retaining frame numbers is important. In order to do this I need to set the start frame of the composition to a negative value.

I was trying to do this with

app.project.activeItem.displayStartTime = -1

but of course I encounter an error because displayStartTime only accepts values between 0-99999

Is there any other way to do this from a script?

Can we get displayStartTime patched to properly accept negative values?

Thanks