" ... he could also try to fetch the whole table as html once using WWW::Mechanize::Chrome and do the parsing with Mojo::UserAgent"

I've used this work around in the past for things that need special sign in or bounce back things that aren't being detected as a 'real' browser, purely so I don't have to do a lot of code changes :) As the location of the bottleneck is not yet understood this may not resolve the issue of performance.