update: wasn't able to address the specific warnings on my site. found this update on the google search console forums claiming it wasn't a big deal & wouldn't impact search performance. i'd still hope it's an update squarespace has in the works!
update 2: found a blog post explaining how to add custom code to address these warnings (won't work for me, as i'm on a cheap plan, but may work for you!)
I'm having a similar issue: six warnings in google search console on my squarespace site. i'm going to go into each warning, identify the content issue, and attempt to address within squarespace, and i'll report back with my results.