In my experience, if you think you will have si and do partial hanging, it's best to be difficult to get urself back up. My partial hanging method is using a very sturdy coat hook on my door, and I have to go down in a way that it's difficult to stand back up without using my legs and arms at the same time. The closest I've been (and would've succeeded I believe if a roommate didn't hear) was using that method, where my legs went out under me before I could stop myself and my arms by themselves was not enough.
With a full hanging, if si is a concern, for me at least, it kicks in before you even start, because once you you step off whatever you stand on, that's almost definitely going to be it, so walking far could either help you get over si, or just end up being incredibly annoying if you can't push yourself into it.
Full hanging is obviously going to be better for getting the job done, but partial hanging in my opinion is easier to do and less likely to hurt.
Also, the time I used an extension cord did not work very efficiently. The position was always awkward and it didn't tighten well. If you haven't already, I'd suggest making sure that won't end up an issue for you.
I also don't think you should use a flimsy bar in ur closet for it. If you want to, test it with ur weight on a rope using ur hands on the rope, not ur neck.