API remote images

Hi- I’m using WZone plug-in for Amazon Associates with the remote images option on. My side has around 500 products now and the site has become super slow, with products taking up to 30 to 60 seconds to load! I’ve been told that using remote images is the main issue causing such slow site speed. Does anyone know if the Amazon Associates rules require use of remote images or can the images be stored on my server? Do you think adding products with remote images off will speed up the site significantly? I’ve tried almost everything so far & this issue has persisted for many months! Any feedback would be greatly appreciated! Thanks!!!