There are two different kinds of ILDA files out there (apart from the different formats).
There are some that are (sort-of) optimized for display on some kinds of laser DACs and there are some that are stripped down to just the bare minimum of vertices to make the image.
The extra blanking points are there to control the velocity of the scanners.
Using LaserBoy, you can open just about any kind of ILDA file and either strip out those extra points or add them. There are several settings that control these effects.
James.