alright then - but its fairly easy to have some sort of zone - transfer tool (for transfering zones form one Bind to another Bind instance (if you don't use pdns) )
so at this stage it'll be easy to just create a copy of your zonefile with just an empty zone and
only 1 A record in it ...
And if i get you right - you're asking to provide a feature, to create the 2nd set of zone files by ispCP engine ? - and then ... the transfer of zones is still work in progress - so there should be something in your setup to copy zone information just abroad ...
To make the fail-over then automatically is just a matter of a few scripts as well then.
But to be honest - i thing its maybe a nice idea - but only for .01 % of our current ispCP users - even those who have hundreds of ispCP servers do have redundant-everything in their facilitys. So the possibility to have a complete disaster for a whole facility is normally below 99% - 99,9% else you're doing something seriously wrong