Updating ResourceMinimizer to handle ES6

[JumpStart]

Is there any plan to upgrade the ResourceMinimizer to handle EcmaScript 6? I’m 
having to downgrade some javascript to avoid the minimiser rejecting it in 
production. For example:

2019-07-29 05:25:33,162 SEVERE [com.google.javascript.jscomp] (default task-14) 
StreamableResource<text/javascript 
classpath:META-INF/assets/clientapp/indexedDBHandler.js COMPRESSABLE 
lastModified: Mon Jul 29 05:25:14 UTC 2019 size: 10105>:29: ERROR - Parse 
error. syntax error
                return new Promise((resolve, reject) => {
                                                      ^
…
2019-07-29 05:25:33,181 ERROR [org.apache.tapestry5.ioc.Registry] (default 
task-14) Compilation failed: JSC_PARSE_ERROR. Parse error. syntax error at 
StreamableResource<text/javascript 
classpath:META-INF/assets/clientapp/indexedDBHandler.js COMPRESSABLE
…
        at 
org.apache.tapestry5.internal.webresources.GoogleClosureMinimizer.doMinimize(GoogleClosureMinimizer.java:97)
        at 
org.apache.tapestry5.internal.webresources.AbstractMinimizer$1.perform(AbstractMinimizer.java:72)
        at 
org.apache.tapestry5.internal.webresources.AbstractMinimizer$1.perform(AbstractMinimizer.java:68)
        at 
org.apache.tapestry5.ioc.internal.OperationTrackerImpl.perform(OperationTrackerImpl.java:110)

Cheers,

Geoff