Hi Kdenlive does a good job in adding and removing spaces in the tracks, both for a singla track and for all tracks. However, there is a drawback. It does not account for guides and while shifting all the media items in the tracks, it does not shift the guides. Sometimes this creates a lot of work, so you have to manually fix the position of the guides if such a multi-track space addition/removal has been performed.
If my description is vague, please let me know. I can explain more and even send a demo. Thanks for making the best Linux video editor. Best, M
