I see in 5.0.0 that arrow functions were introduced. This unfortunately made the module incompatible with the Chromium Embedded Framework version I have to use for my product.
I'd understand if ES6 compatibility is required going forward, but it'd be great to keep using whatever improvements you introduce without needing to keep my own local edits or being stuck on an old version. As such, I'd ask that you reconsider.
FWIW in case you're interested, my product is an extension for Adobe Photoshop. Adobe has switched their extension platform to use CEF along with a local Node process for utilities and such. Unfortunately this means I'm locked into whatever CEF version that shipped with specific versions of Photoshop.