I bought these lamps a while ago when they were on sale (maybe EOL?). When i unboxed the first I heard a clicking sound and noticed the lamp wouldn't fold up anymore, so I opened it up to see what caused it.
Ikea designed the lamp with a spring loaded pin which would activate when the lamp was unboxed. It limits the range in which the top part can be rotated, but if you know it's there it's easily removed.
The head also didn't have much range, but this was easily cured. Remove the handle and increase the opening in the neck with a saw/file/dremel.
I have three of these, and they are quite agile lamps now. The pictures show the range gained by this hack. (modded vs unmodded)
There is no picture, but the rotating joint at the base can also be modified to increase the angles there. If the base would support it, they could be stretched out horizontally. But they tip over if you don't clamp them down.
So maybe you should check your desk lamps, there might be some room for improvement.
Enjoy this project?