In case you haven't seen it, when you view a particular sale page you can now:

1. Filter what is on sale according to your wishlist

2. Filter to show only those DLCs for the games you already own.

VERY nice GOG. Thank you

Yes, that is known for about a week or two now. Mesa like.

Only games on wishlist + sort by biscount = win.

You can hide the pop-ups with uBlock Origin or similar.

! Pop-ups when hovering over a game thumbnail in the store
gog.com##product-tile-extended-portal

Alternatively, using the userContent.css file in Firefox that requires no add-ons, or the Stylish add-on for multiple browsers:
@-moz-document domain("gog.com") {
product-tile-extended-portal { display: none !important; }
}

Thanks very much for that info.

@OP - Yes these two new options are great, use them every day. BIG THANKS GOG. :)