Greasy Fork

@jcunews you may want to know that YT has new small changes related to ads.

Your script still is working almost perfectly, ad images are blocked, but sometimes the ad time interval is not blocked: Before video starting a black background appears (no ad images) for 5 to 10 seconds... only then the video starts. The previous normal behavior of your (fantastic) script was: Ad images and ad time intervals both were blocked, YT video was starting directly.

Cheers

If you're using Tampermonkey like I do, change the Tampermonkey experimental setting: Inject Mode to Instant, instead of Default (the default). Tampermonkey's default injection mode is the reason why document-start based scripts run inconsistently (i.e. sometimes work, sometimes don't; either partially, or fully).

Thanks @jcunews , but I'm using Firemonkey... no such "Inject Mode" option (as far as I know).
Just in case I tested your script on Tampermonkey, changed the inject mode... and your script seems to work well.
At first glance, if your script works with Tampermonkey, then the problem might be Firemonkey. But I have my doubts, because for months your script worked perfectly with Firemonkey (your script just need the following small hack replacing line 16 (fn = (a) => {) with: fn = (a) => { let fn, ipse, haia, hca, rpo, et;

Perhaps part of the problem is Firemonkey.
But I believe that another part of the problem might be YT... because (by using Firemonkey + your script) YT ads are 100% totally blocked, only some time intervals (before video starting) are not blocked and appear with black background.

Hope you can help.
Thanks a lot in advance!

Acknowledged. The script has been updated.

@jcunews thank you for your replay and for your update.

Please, keep in mind that using FireMonkey the small issue (ad image before video starting) still is there.
The YT page loads perfectly, 99% of the yt ads (skippable and non-skippable) are blocked, but at least 70% of the time a static ad image appears before video starting. When "play" is pressed, no yt ads, and the video starts directly. The static ad image changes when you load another YT page.

I'm not an expert, but by playing around, I found that these urls are related to the static yt ad image:
https://i.ytimg.com/vi_webp/
https://i1.ytimg.com/vi_webp/
If I block them, the static yt ad image is gone, but the delaying time still is there (5 to 10 sec before video starting).
Hope this info may be useful to you.

I know you're a TamperMonkey user. But please, also keep in mind that FireMonkey got lot of improvements, upgrades and updates. So how knows, perhaps small adaptations in your script can easily solve small issues. If you don't want or can't do that, don't worry, I understand, is fine.

Thank you again

But unfortunately, by design, FireMonkey is still too restrictive for GM scrips. FireMonkey doesn't conform to the GM specification. IOTW, FireMonkey is still a UserScript provider. It's a GM provider, yes. But not a compatible one.

Thanks for your comment @jcunews. I'm aware about Firemonkey limitations, but for my use it works, it's very friendly in terms of privacy, it's the only monkey using the latest API, and on my tests it had the best monkey performance. Remember that your YT script worked like a charm along Firemonkey for more than one year, only now I'm seeing small issues (youtube static ad image before video starting).

And you may want to know that your YT script also has issues with:
Greasemonkey: The YT page is not loading at all.
Violentmonkey: Same issue as Firemonkey (youtube static ad image before video starting.

Your YT script works 100% perfectly at Tampermonkey.

But even with the small issue (youtube static ad image before video starting) in Firemonkey, I still believe your YT script is the best YT ad blocker js script. I'll be patient waiting for your next updates and improvements.

Thanks again @jcunews