Fixture Group update

Hi,
I've asked for this before bit here it is again.
If i create a fixture group and use that group while programming it would be really helpful if when i update that group with additional fixtures that it might be possible for those fixtures to now also be included in any programming.
So if have a group that i use for all my downstage moles like desk channels 1-25 if i now replace that group with channels 1-27
that is reflected in my programming.
I don't want to use replicate which is also very helpful but another feature.

So perhaps something like
1 thru 2 pig copy 26 thru 27 group group 100 update enter?

Obviously a lot more involved than me coming up with a keystroke suggestion but thought i'd ask.
Thanks C