I understand your sentimemt about not going back. After all, doesn't your new gun have a thumb safety?
I'm sure you are going to practice many, many, many hundreds of draw strokes, if you are not already accustomed to doing so, that will bring to muscle memory the need to place the safety off during the draw during any adrenaline soaked, no time to think about the gun or your thumb lethal engagement. Otherwise, well, an unfortunate outcome may be likely as one could only imagine...
Wouldn't you agree?