Welcome to the GitHub Community forum! Everyone here is very helpful, but this sounds like it's about a pretty specific project. If you don't get the desired response here, you could try opening an issue here: https://github.com/cefsharp/CefSharp . People there will probably know more about the technology and you may find an answer more quickly.
According to the V63 release notes, V49 is the last release to support .NET 4.0.
Please follow-up to let us know how you made out. For good karma, mark a reply as the answer if it helped!