Proxy use and IE11 Support

[magicgrl111]

We've been happily using typewriter almost a year now(since Feb 2019). We have a business requirement to support IE11. Since updating to [email protected], we've needed to add a polyfill to use this library due to its use of Proxy.

We've temporarily added a polyfill, but this is not a 1:1 match in terms of functionality with the native Proxy. Is there any way to refactor the generated code to not use this non-standard feature or to include a polyfill and/or warning for browser support?