I’m absolutely liking these idents - the branding feels much more ingrained than it was in the 2015 idents. Much less odd compared to the current idents, too.
The soundtrack is a nice nod to the original ident set in 1982, but as others have noted, each ident would need additional soundtracks to avoid a sense of repetitiveness. As they are test idents, there’s always the chance of soundtracks being tweaked before the block man idents actually go on air.
Overall - 4Creative has knocked up what is a nice evolution of the 2015 branding into something much more appealing and warm. And as for the block man, I’ve a feeling that it will grow on viewers much more compared to the current Channel 4 idents, which did have a slight pretentious feeling about them.