It almost sounds like to do global blocks well, you need some totally separate workflow. Sascha's idea of groups/setlists starts to make more sense to me. It's basically tree structure presets, where the top tier determines simply "these blocks are global for these presets". Something like this:
Dunno, maybe that'd be an idea - but seriously, global blocks and block presets should be two completely different entities and never ever even be close to the same menu structure.
Here's roughly how I could imagine dealing with it.
- Create preset (you could obviously use block presets when doing so, they wouldn't be affected in anyway or play any role down the line...).
- Tell preset to be in a group (copy to setlist, tag it, no idea what'd be ideal, but that's not a big deal).
- Select, say, one amp and tag it to be global (well, within that group...). Not sure whether it needed a naming function (ideally it's show some info automatically). After all, we likely won't end up dealing with tons of global blocks per group. The icon of the amp should reflect the global setting.
- Create another preset.
- From the amp selection menu, there could now be a submenu showing you the amp tagged as global in your first preset. When you select it, it'd instantly work as a global/group block.
And that's pretty much it already. You could at any time select another amp, remove the global tagging, and what not.
---
One somewhat important question would be whether one should be able to completely change the amp model or even a completely different thing for any specific block.
To stay with amps: Let's assume I'd want a Plexi instead of a Bassman - should that change be reflected globally as well or should one of the requirements for a global block be that it'd stay with the very same model?
Or, to take that even further: You could even do wild things in case anything was possible, such as replacing your amp block with a send/return block to use the same group of presets with a real amp.
I could live with either approach, being able to even select anything you'd like and have that change reflected across multiple patches might confuse some folks (even if I'd love the idea myself).