Apple introduced new multitasking features in the latest iPad OS version. iPadOS 26 brought real windowed multitasking like MacOS but 26.1 brought (more accurately, brought back) slide over as a windowing option.
I found a great use case for this is to run Bandhelper in traditional full-screen mode and then run a secondary app, such as a monitor mixing app, in slide-over. The slide over window is smaller (but still scalable to whatever size you want) and hovers over the bandhelper window. With a quick swipe from the right of the screen, you can bring in the secondary app without leaving Bandhelper and make quick adjustments. Then swipe again to hide it. This is so much faster than older methods and I never have to leave the Bandhelper app.
If the secondary window hovers over BandHelper, does that mean the BandHelper window doesn't resize, which would rescale your layout? That would be nice.
If you have Bandhelper in full screen mode, it's unaffected by whatever app you have in slide over. No resizing or anything
I don't have my iPad at the moment but I can screen record an example later.
My main layout is a portrait split-view mode with the song list on the left and document on the right. I sized the slide-over window to be about the size of the document viewer so that when I slide it in, the song list is still visible.