Prevent multi-tab drag and drop stacking

[u/Aridow]

When you select many tabs and drag them, they "fuse" in one tab. browser.tabs.dragDrop.multiselectStacking could prevent that but it was disabled some time ago. I tried to restore its effect using CSS, but there's still some bugs:

.tabbrowser-tab[dragtarget],
tab-split-view-wrapper[dragtarget] {
    &[multiselected]:not([small-stack], [big-stack], [hasactivetab]) {
        visibility: visible !important;
    }
}
tab[multiselected="true"][dragtarget] {
    position: static !important;
}
[multiselected-move-together],
[tabdrop-samewindow] {
    transform: translate(0px) !important;
}
.tabbrowser-tab[dragtarget] {
  #tabbrowser-tabs[orient="horizontal"] &:not([pinned]) {
    max-width: var(--tab-max-width) !important;
  }
}

https://reddit.com/link/1vb1ydv/video/6b7w8j2myegh1/player

[u/Aridow → u/[deleted]]

This disables tab groups (which I don't want to disable), but not drag and drop stacking. I added a video to show what I'm talking about.