Epidemics is a pretty bad gameplay system. Especially considering patients going between buildings automatically fails it; which makes it almost completely broken. On some maps buying some particular buildings is a complete foot-gun due to this.
Curious what you prefer about the original epidemics. As a rule we try to balance quality of life improvements with faithful implementation and lean towards faithful when a change is controversial.
For our own protection we do not reverse engineer though so the goal is similar to what can be observed and fun to play.
about a year ago I got most of the way through CorsixTH before realising a few things didn't behave as they did in the original, namely epidemics
I went back and completed the original instead