Yes, it's very important to keep the original game intact in these remakes. I started this trend over a decade ago in virtual pinball, when I remade The Addams Family adding a new audio package and new features. Later I remade Bally's Flash Gordon, but this time added the option to switch back and forth using a 'Modern/Retro' switch to keep the original audio and code intact (go to 34 secs in this vid to see the effect).

For those attempting to follow in my footsteps, it's not easy I can tell you, switching from the original game to a modern remaster at any time. And currently impossible in the real world to also switch the display from gas segment to DMD and back again. But as you've demonstrated, it's possible with a little creative thinking.