Cymbal House review for Thunder Page Speed Optimizer

Critical css, image resize not working on my website. Not sure if prefetching works. Within the code of loading bar and therefor sort of hidden, a link to https://www.w3.org/ creates "the largest contentful element" with error, read by website speed anaylizers also as an error, somehow registers for a higher speed. The only true benefit using this app was compressing the css file and nothing more.