How to join a client PC to WS2012E R2 that's already a member of another enterprise domain using the skip domain join registry entry?

Question

In WSE12 R1 you can install the connector application on a Windows 7 PC that has already been joined to a corporate domain using the skip domain registry key:
reg add "HKLM\SOFTWARE\Microsoft\Windows Server\ClientDeployment" /v SkipDomainJoin /t REG_DWORD /d 1
Upon doing so, the client PC is then able to perform client backups to the WSE12 R1 server but remains a member of the original corporate domain.  This is no longer possible when using this registry key when installing the Windows Server 2012 Essentials
R2 connector
Is anyone aware of a way to install the WSE12 R2 connector and skip domain join without first leaving the corporate domain? 
I am avoiding moving to WSE12 R2 until I can figure out a way to accomplish this.

Answer 1

I noticed this was incorrectly marked as an ANSWER. Although it wasn't a resolution, I recognize the connector install behavior is different in R1 vs R2. If it would be possible to ask the developers to include the following functionality in a future
Essentials R2 Update, we'd appreciate it. During client connector install, give user the option via radio button: 1.) install connector join domain, enable client PC backup 2.) install connector, join domain only, no client PC backup 3.) install connector,
do not join domain, enable client PC backup Option #3 would satisfy this request and negate the need for unauthorized registry hacks. Thank you.
Great discussion here, and glad things seem to have changed for the better with R2.
Spot on with those suggestions, miles267!
Back in Dec 2013, I wrote about my fairly simple registry tweak done at just the right spot during the client connector install, still seems to work like a charm
(as of Dec 12 2014, ~15,000 folks read it so far):
TinkerTry.com/connect
which redirects to:
http://www.tinkertry.com/how-to-make-windows-server-2012-r2-essentials-client-connector-install-behave-just-like-windows-home-server
with a lot of (admittedly confusing) comments:
http://www.tinkertry.com/how-to-make-windows-server-2012-r2-essentials-client-connector-install-behave-just-like-windows-home-server/#comment-1705687227
Sincerely hoping such feedback helps encourage Microsoft to take a simple radio box checkmark request seriously. Really, it'd really help folks a lot, so they wouldn't have to feel they are trusting a "hack" which is really a simple, documented
registry tweak, done at just the right time.
I hope this little post here, and my article, truly helped people out!