Yes we also try converting images to .avif with the NPM module Sharp version 0.27.0 and we images as large as .webp using the default speed of 5/8 and it takes 10 seconds to encode on the same AWS Lambda of 512mb. I red that increasing the speed to 8/8 will lead to smaller file but the encoding time will take 3 minutes.

https://fronius.me/articles/2020-10-14-comparing-image-forma...