I had the same noise as the OP had in their video so thought I would just post on here. Mine didn't stop making the noise when the motor warmed up and I thought it was probably the CCT. Took the heads off and this is how lose the front cam chain is.
20190802_173907 by
Graeme Taylor, on Flickr
20190802_173946 by
Graeme Taylor, on Flickr
Just need to work out what the cause is now. Also is it normal for the timing marks to be ever so slightly off? The engine runs fine apart from the rattle but the timing marks seem just slightly off from what the Haynes manual depicts
The rear timing marks seem to do similar.
20190802_173829 by
Graeme Taylor, on Flickr
20190802_174009 by
Graeme Taylor, on Flickr
20190802_174037 by
Graeme Taylor, on Flickr