I think that’s unfair though. It’s not necessarily about percentages; potentially they could easily be seeing a few tens of millions of monthly visits from IE a

I think that’s unfair though. It’s not necessarily about percentages; potentially they could easily be seeing a few tens of millions of monthly visits from IE and Edge, and if putting in place an automated system to convert images to a (theoretically) more efficient system had increased conversions they’d be really happy for the payback. Thinking about it, assuming they’ve got a WebP output for Chrome already this could be as simple as adding one more build step with a different encoder, and one more negotiation rule on the CDN.