I put mine on the outside of the door, spread it out to cover the area, and move around it to get in and out. It got in the way on the inside of the door.
With weight drags on the outside of the door curtain, you'll have to sweep aside the curtain, but the cushioned weights will allow it curtain to resettle into a full door width blackout coverage.
If you use a regular door I would suggest you investigate a solid wood or metal door. They tend not to warp over time like hollow core doors do. Yes, they are heavy and cost a lot more but because they tend to be more flat for a much longer time they are easier to make completely light tight for a longer time. My currant darkroom is very small (6x10 ft) in order to save space I built the hollow core door frame to open out, this made it harder to keep light-tight but with a bunch of foam tape I succeeded.