As an ISV partner we still have to support both Lightning Locker as well as LWS when developing our products. Because not all customers are on LWS or on Lightning Locker and it's not a good product strategy to force the customer to update to LWS to use our components only, this would severely hinders adoption.
And it seems that every week there's a new thing we find that is available in major browser support, that isn't supported in Lightning Locker.
Recently we've had many issues for example with the AbortController to be able to abort a Fetch request. We've had to add a polyfill to our code for that. And now we've discovered that the Headers interface of Fetch is not supported in Lightning Locker... Which means another polyfill.
https://developer.mozilla.org/en-US/docs/Web/API/Headers <- For reference:
"This feature is well established and works across many devices and browser versions. It’s been available across browsers since March 2017."
It's not like it's new either.
Is Lightning Locker being maintained up to date? Is everyone supposed to switch to LWS? How are we supposed to deal with this as an implementor/ISV partner? It would be nice to have an official statement about this.
