I would go with Jimmy T’s suggestion if you can. However, the bottom line is that this is a bit of common property that it sounds like you are getting an exclusive benefit from. It seems fair enough that you take responsibility for its maintenance and formalise the arrangement. Then it is unambiguous for all concerned.
I wonder if the EC is concerned that there are many analogous, non-formalised arrangements where unit owners have paved or otherwise made use of adjacent bits of common property that are really of little use to anyone else but a real benefit to the individual unit?
We have such a situation in which every unit has their own style of path or driveway that connects to the shared paths and roadways. All were installed across short stretches of common property by unit owners in diverse styles. Long standing policy of almost 40 years has been that these are a unit owner’s responsibility but it has not been formalised. We are drafting a general meeting resolution to do that now. Our legal advice says we can make all of these exclusive use ‘special privileges’ (in the ACT) but that would then require an unopposed resolution to pass and someone is bound to get the wrong end of the stick and oppose. It would be a serious pain if had to install standardised paths to all units just to ensure some were up to scratch.
I would prefer to use an ACT provision of our Act that allows the EC to approve a ‘minor use’ of common property subject to conditions (e.g. maintenance in a safe and attractive condition by the unit owner) when it would not interfere with the reasonable use and enjoyment of the common property by other unit owners. The problem is uncertainty about how big a ‘minor’ use can get before it is no longer minor. I argue that it is dependent on context. If you have many hectares a few square meters can be minor. If you only have a few square meters of common property it would not be minor. Does NSW have a similar provision or do you need special by-laws for even the most trivial of incursions onto common property?