# How to remove unnecessary filling in ListPlot3D [duplicate]

I have the XYZ data points of this link (also here). If I plot this data

proportions = Map[ToExpression, Import["https://pastebin.com/raw/uzucQpJb", "Table"], {2}];
ListPointPlot3D[proportions, ColorFunction -> "Rainbow",
Filling -> Bottom]


The figure shows a zone with no points. However, with

ListPlot3D[proportions, InterpolationOrder -> 3,
ColorFunction -> "Rainbow"]


forms a plane with non existing points between the highest Z values and the lowest.

Also making a the Interpolation and plotting the function:

f = Interpolation[N[proportions], InterpolationOrder -> 1]
Plot3D[f[x, y], {x, 0, 0.7}, {y, 0, 30}, ColorFunction -> "Rainbow"]


which plot surface in the same part where there is no points.

I want to ask if there is a way to remove the plotted part of the figure where there are no points, and make the ListPlot3D surface only with the original points that were plotted with ListPointPlot3D.

I also would like to plot the InterpolatingFunction, f[x,y] removing the part where there are no points.