Speeding Up Gravatars

Hi, thanks, great plugin that creates a multi author about us page for me that doesn’t involve building a huge complicated page with a builder. Looks great and responsive. However of course, all these gravatars create a burden on page speed. I have looked around for gravatar cache plugins but many are unsupported etc. Do we know of best way to solve this issue? Thx

The page I need help with: [log in to see the link]