What is the opinion of Reddit about the
2PCS Black Adjustable Bed Frame Anti-Shake Tool, Headboard Stoppers with Free Furniture Pads and Screws, No More Creaking, Protect The Wall from Banging, Easy to Install (1.1-2.5in)?

Maybe get a GPU support bracket or some kind of adjustable stopper.

Noticeable sag isnt usually terrible or indicative of causing damage; but overtime its only going to get worse.

in general I saw a tiktok about this product
also a very thin pillow helps.