hybrid 2024.09.29.1

[Selur]

Does it have any issue I need to worry about?

I hope not, anything I fixed after a release is mentioned on the changelog page.

One of the updates before had 2.dll files missing, with the last version I got the helper 1 error,
many other users got the same error too.

Afaik. anything that was reported and that I could reproduce was fixed.

In the new updated version what is the best way to change colour matrix, say I have an RGB video file and the media info panel in hybrid is wrongly identifying it as YUV -YUY2 when it's RGB, can I change it in hybrid even if hybrid is identifying it has YUV 4:2:2 source input?

No, in my book, something is broken in this case. (there are workarounds, but nothing really that is meant to overwrite the source color space)
Properly report it and if it's a bug in Hybrid and not a bug in another tool or a broken source I will try to fix it.

Hybrid sees lossless SD as REC601 when it should be BT709 I think?, can we change this in settings without it having any negative effects on the video?

This has nothing to do with lossless, but the format you used.
(Note that RGB content has not color matrix, if you specify a color matrix for rgb input it's the color matrix Hybrid will use when it needs to convert your content to YUV and back.)
You can overwrite the input color matrix under "Filtering->Misc->Overwrite Input->Overwrite input color matrix".

If a video is uploaded to YouTube using Hybrid,YouTube statistics for nerds options always shows as colorspace unknown, maybe its because of the BT709 and REC601 mix up?

Can't say anything about what YouTube shows somewhere an why.
You can look at the output of Hybrid with MediaInfo, FFmpeg and other tools to see what signaling the output contains.

When using other software in HD quality YouTube always shows colorspace BT709 in the nerds colorspace section and it never says unknown.

If other software works better for you, use it instead of Hybrid.
Color space BT709 makes no sense that is a color matrix for YUV<>RGB conversions, not a color space like YUVXXX, RGBXX,

Cu Selur