Its really easy to edit one of those scripts for your own HDRs, the only requirement is to have the tiff and jpg with the same name and in the same Uberenvironment folder.
If I recall…the right size too.
When I was messing around creating some presets for UE, I found that if I didn’t have the TIFF and JPG at a similar size (pixel dimension) as the ones used, there would be either odd stretching/cropping or tiling artifacts. Especially on automatically converted images. Ones I manually converted and scaled/cropped to the dimensions of the supplied pics didn’t have those problems. Plus manually converting the image gives you a lot more control over the final ‘look’ of the image.