Probably the easiest way to do this is to get a flywheel to temporarily install. Install your belts and transfer the marks to your current flywheel to make it easier next time. You may even find somebody locally to lone you one.
Welcome to the state of modern consumer products. Too many computers and too much intellectual property. You don't own your car and it's software. Subaru owns the rights to it and will dictate what you can and cannot do with it. Forever.
And no, there is not, nor is there going to be, any "software" to change any of that behavior.
GD