Ultimately, we decided that if you can't run classic DOS programs on a "modern" DOS, then it's not DOS anymore.... We won't be multitasking or multiuser or any other "modern" operating system functionality. That's not what it means to be DOS.
Keep the software functionality; it's perfect for specific circumstances. Please try to modernize the hardware interface as much as possible. A lot of contemporary computers lack what was considered basic hardware when DOS was new (and gained new stuff).