I've received quite a few similar maps by the same author, with just some minor changes (like spores, emitter intensity or an additional wall). One time 4 versions of the same map were uploaded and another time 5 versions of the same map.
Please note that we will allow only a maximum of 2 versions of the same map (i.e. 1 easy and 1 hard), and I even discourage doing that. People are not interested in playing the same map multiple times and we also need to give other map makers a change to get their maps in the spotlight for a while. So please make up your mind how hard your map should be and what type of players you're aiming at. Always make sure you can finish the map yourself.
This is also the reason we don't approve more than 2 maps by the same author per day (or 3 if all have
scores submitted before approval; these maps will get priority during the approval process).