I find myself already using the new Tab Islands plenty, for many things, but foremost for Organization.
But if you use many different Tab islands at once, like me, you can lose the overview quite fast.

I would think that the following features would greatly increase the usability of Tab islands

Customization:

• choosing your own color
• giving the island a name (especially for the
  right mouse → move to → island function)
• using a symbol/emoji instead of a color

Options:

• option for showing the (foremost) website symbol instead of a color
• option so when collapsed, the foremost tab is still visible like when collapsed while still inside the island (for better recognizability)

I find myself already using the new Tab Islands plenty, for many things, but foremost for Organization.
But if you use many different Tab islands at once, like me, you can lose the overview quite fast.

I would think that the following features would greatly increase the usability of Tab islands

Customization:

• choosing your own color
• giving the island a name (especially for the
  right mouse → move to → island function)
• using a symbol/emoji instead of a color

Options:

• option for showing the (foremost) website symbol instead of a color
• option so when collapsed, the foremost tab is still visible like when collapsed while still inside the island (for better recognizability)