Isn't possible, as far as i can tell, stay with ubuntu and custom recovery. But using OLiFE you can easily flash custom recovery, update and everythink else.
A problem should appear when you want to use Custom Recovery. You can easily flash the recovery in the menu update>advanced>flash custom recovery.
In normal cases, when you want to comeback to ubuntu as second boot, you should only select update>advanced>linux kernel and it should be fine. But this image flash Jhinta Kernel, and doing what i told you'll be flashing the original kernel of OLiFE image.
This can be solved if NoDiskNoFun post the Jhinta z-image and initrd for we rename and replace for 2636-zimage and initrd2.6.36.img files