Hi
Good question, I was wondering that myself. It looks like with so few nodes per area, we end up with some very thin areas that for example result in the two areas on each side, plus two adjacent areas above, being included in the extended bounds/overlap if a node is in the centre of the thin area and close to the top.
OK, if that is the case I was thinking that the overlap might be better as a percentage of the size of the area. In areas where there is a straight road that continues for miles and miles nodes might be widely spaced, but that is unlikely in densely mapped areas. The Garmin units have different sizes depending on direction and latitude, but 2000 is over 4km(?) and that might be too much in any circumstances.
Here's an example of a node that wants to be in 5 areas:
<node id="447665000" lat="46.0753181" lon="13.1930056" version="1"
That is an interesting area, as it appears that buildings are mapped so there is a much higher node density than normal, but only the main roads are there. ..Steve