Greetings!

If you know you will install the button hack - 100% certain, I would recommend you get the electronics fitted / display board modified. Even if it is months before the castings are available.

The reason: once the castings are available, I am certain a lot of people will want to get this hack done. All of them at once. If you can get the electronics done early, it is less likely you will need to wait in queue later on. All you would need would be to have the castings shipped to you, and you fit the buttons yourself.