When you need to send for RMA, you just need to remove all the sleeve and restore it to the original appearance. Abit troublesome. Why not get sleeved extension?

Your PSU fully modular? As long as you do not open up your PSU its fine. Maybe you can send it out without the sleeve, if the worst thing happen tho. I've seen people ask this question at corsair forum, and they do allow as long as you do not open the PSU and your cable is not hardwired. You want to do individual sleeve, gonna take alot of hard work. Do it neatly sure the result going to looks cool.

It's better for you to ask silverstone directly. Don't want to end up couldn't RMA it later. BTW how many years of warranty does silverstone provide?

Make sure you got the black and white. For all the RMA process i've gone thru, all of them want me to return the complete package. For my previous corsair HX620, all cables must be return. For my logitech G500, even the weight catridge and holder also need to be return.

Distro for the PSU, cudo tech. Satisfied with their services. Fast and done accordingly.