Although it is attractive, I find that toning questionable and would not pay a significant premium for it.
...even this is perhaps "artificial toning" yet MS67+ certified it is sold by heritage for almost 4 thousand dollars a few months ago
artificial toning ??? MS67 sell at 1000$ https://coins.ha.com/itm/kennedy-half-dollars/1964-50c-ms67-pcgs/a/1238-5022.s?type=NGC1238
Again, my observation was directed specifically at the coin in your first post, not the coin in this link.
Y'all must of missed the Kennedy @Tim C posted a day or so ago. https://www.cointalk.com/threads/post-your-kennedy-halves.199544/page-65
Usually, intentionally applied chemicals. And not good ones. Especially that shade of blue, and especially when the toning is exclusively in the fields and not on the devices, creating a "cameo" type contrast. Absolutely red flags on artificial toning! Therefore, it's not worth the silver its deposited on. That giant ugly banner across the middle of the coin is really distracting and absolutely unneccessary. Nobody is going to steal and repost your picture of an ugly artificially toned coin, and it only hampers our evaluation of it. If you want to put a watermark, put it in the area between the coins. This only makes you look silly.
a question to the experts experts of coins. You can give MS64 to a coin with at least 3 SERIOUS incisions on the obverse (cheek, neck, chin) ... in my opinion you should stop at most AU58
If PCGS deemed it to be uncirculated, then by definition it's mint state (MS) and shouldn't be graded AU. But I agree with your opinion about the ugly gouges on the obverse and personally I would give that coin a much lower grade than 64.