Recently inherited albums purchased in the '70s, '80s. Some were "LASTED" when new. The previous owner took good care of his records and always had a good not great tt/cart.
It seems that the treated records sound clean for the most part. Some better than others, yet some untreated ones sound clean too.
Not sure if he labeled all that were LASTED or if some were played much less.
I never treated my own albums from that time, but took good care of them. Cleaned vinyl and stylus before each play. Some still sound very clean others so so.
Now that Ive purchased many high quality pressings such as MoFi, I would not coat them with any product.