Query Loop Block Image Size

Hi!
Is there a way, filter or something, to set the size on Post Featured Image in Query Loop Block?

I’d like to choose thumbnail or medium or medium_large, but not to relay on the default full size, especially in a grid/column layout, because Google is going to ban me because of serious performance issue (excessive size).

Interesting that Latest Posts Widget has the image size option, but doesn’t meet my other requirements.