Actually, it's tough to tell, but the picture shows the jack in the lowered position before it is raised up to lift the bike. The shocks actually do not protrude below the frame so when you lift it, the frame will rest on the jack and not damage the shocks. Definitely check for proper clearance on your particular bike when you do it, but you should not have an issue. You definitely don't want the shocks supporting the weight of the bike because not only could you damage them, but you need them to be able to move freely front to back when you jack up the rear tire to extend the shock shaft so that you can install the collars. The jack in the picture is the standard red Craftsman jack and that one worked fine, so similar ones should as well.

 

Here is another pic of a bike on the Craftsman jack with a floor jack under the rear tire lifting it up into the fender to get it ready to install the collars. You can see the bike resting on its frame on the jack.

 

Damn nice there OP! An un-lowered softail is like a grade school geek with too-short pants and white socks!

 

Tried that with mine but the back rail ended covering up where I need to work.




Looks from that pic like the back rail of the lift is behind the shock bodies. I tried positioning my Sears aluminum (yellow) jack there but the front rail covers up the front of the shocks. Just checked again with a straight edge, my shocks definitely stick out slightly below the frame.
Thanks for trying to help, I'll just have to take the bike somewhere to get it lowered.