There have been a couple of changes with the last 2 Insider builds -- usually that means the same or similar changes show up in the next general release version.
The last couple of Insider builds have a larger setup ISO file, meaning either you need to burn the ISO to a dual layer DVD, or if you create that ISO try doing so with a compressed WIM, or skip burning to DVD entirely using something like rufus to stick it on a USB stick [ neowin[.]net/news/rufus-211995 ].
The 2nd change I noticed is that the upgrade setup process copies the install.esd file to the Sources folder, but unlike previously, that file is removed once the upgrade is finished. That means a few less GB of leftovers to get rid of, but it also means that if you want to save it [e.g. to create an ISO], you have to copy that esd file somewhere else while that setup is running, before it restarts Windows.