How does Bless work?

I'm getting an SSD for my wife's MBP 2010. I was planning to install the old HDD and the new SSD into my MacPro and just use disk utility to copy all the info from her old disk to the new one. It would be easy enough and once the new disk is installed she can pick right up where she left off. But I had an idea to reduce her downtime while the disks were copying. If I install the SSD into my MacPro first. then copy all the files over the network from her MBP onto the SSD. All I would need to do is bless the new SSD and I should be able to just swap the two drives and it should be perfectly bootable with all files and settings intact right? the MBP only needs to be down for the 15mins it takes me to change the drives. I'm just a little bit confused about how Bless works though. It just lets the computers firmware know where to find the boot-loader right? but is that info saved in the firmware? or is it apart of whatever filesystem the Blessed files exist on? I guess what I'm asking is, if I bless the SSD while it's in my MacPro, will it mess up the MacPro's boot settings? and Not make the SSD bootable? Or will it work like I hope it does and just make the SSD bootable so that it can go into the MBP and just work? Or do I need to add extra options for that? PS: yes I realize that this all just creates a bunch of extra work for me to save an hour (at most) of downtime on the laptop. But I had the idea and now I want to know. Thanks!