I don’t know if Onlyoffice offers the splitting window feature like in Adobe Acrobat. It splits one file to two windows, and I can scroll to different locations in the two windows to compare within one file. If I do any edits in one window, they are synced since the two windows show the same file.
OS version: Windows 11
App version: 社区版 9.0.4.50 (x64 exe)
Downloaded from: ONLYOFFICE website