I really would like both. There is still a strong need for some blocks to be global, unless I’m misunderstanding the global channels concept.
Well, some Blocks don't have Channels.
So, if a set of Block Settings could be saved-and-recalled Globally for one of the non-channel Blocks, the thing you're saving would be (by definition) a Global Block.
But for the Blocks which have Channels, we could either have JUST Global Blocks, or JUST Global Channels, or BOTH.
It's hard to say which would produce the optimal balance of simplicity and convenience.
OPTION ONE: Only Global Blocks (all Channels are Non-Global):
With only Global Blocks, not Global Channels, you can create a block with your perfect set of channels. But if you wanted to have the same Block with only one of those channels slightly different, you'd have to un-global-ize it...or save the new combination as a new, separate Global Block. If you choose to save it as a new, separate Global Block, then the channels you have in common between the two Global Blocks could start out identical, but become out-of-synch over time.
OPTION TWO: Only Global Channels (all Blocks That Support Channels are Non-Global):
With only Global Channels, but not Global Blocks, you save your perfect Fender Vibroverb Channel in one place, your perfect Tweed in another, your perfect Marshall Silver Jubilee in a third, your perfect Vox AC15 in another, and your perfect Cornford in another.
Then, whenever you want to use a combination of those perfect Channels, you place an Amp Block on the grid, switch to Channel A, pick your perfect Vibroverb; switch the Channel B, pick your perfect Silver Jubilee, etc. And you could re-use those same Favorites in other Amp Blocks, in different combinations. But all the Silver Jubilees would remain "in synch," as would all the Vibroverbs, etc.
OPTION THREE: Global Blocks AND Global Channels
Finally, you could have BOTH: A Global Block which contains a mix of Global and Non-Global Channels. The Global Channel for your favorite Tweed would remain in synch across all the Amp Blocks you used it in (both Global and Non-Global).
But that might get too complex for some folks to wrap their heads around. And I'm not sure Option Three offers much improvement in workflow over Option Two.
Whatever they come up with, the UI/UX will need to be well-designed so that
how all this stuff works together becomes obvious and intuitive to the user.