Strange! I’m running 4.8.3 at home and that’s the version that I submitted, so Epic must have upgraded it to 4.9. When you inject the assets into your project you SHOULD get the option to choose which version of UE you’re targeting, which includes older versions (although I haven’t checked if they’re also older versions of the cel shader, or just retrograded with some kind of migration by Epic).
I’ll take a look tonight but realistically legacy support is out the window. I’ve retained older versions but they’re not maintained in any way because there’s very little reason not to keep upgrading to point releases.