That would be nice.
Until then, you can ignore developers by using a cuser style css on your browser.
@-moz-document domain("itch.io") {
div.game_cell:has(a[href*="//username1.itch"] ) { display: none !important }
div.game_cell:has(a[href*="//username2.itch"] ) { display: none !important }
}
@-moz-document url-prefix("https://itch.io/game-assets")
You might want to specify more context, else you will hide them even in your library.
I made a tampermonkey script to do this on the press of a button. It works for individual titles, or for all titles of a developer. And it treats your library different.
(To clarify, you would exchange the moz document, not add it below. Also, the links need to be as written in the url, not how they are displayed. That usually means, it is lowercase, even if the display name is uppercase. Also look out how spaces appear or not appear in the url.)