to progress the proposal along, I want to vocalize that I am for this proposal.
for the specific implementation, I think it can and should be easily included into the same implementation effort as SRFC 32
effectively making “external links” a different type of action. some actions will be transactions, some will be external links, etc.
the one caveat I think the spec update SHOULD include is that blink clients should at least display the domain of the link to the user somehow. eg: under the button or something. the design specifics can be up to each blink client