I personally have not had any issue with my Silhouette Special using 10-46 without widening the nut slots. 11-52 is a different story though. Just wanted to chime in my personal experience even thoug you got a response from Customer Service...they know best .
No need to cut the slots wider for 10s on Silo Special. I'd had the same thoughts before I switched to 10s, but all went ok. The nut hole just can't grab the string when you lift it, and it's not the case for Silo Spec and 10s. I suspect 11s might be different story.
I keep my bridge flat, so I had to increase the tension on a trem claw springs (just a bit) and I also van-halened it (/|\ instead of |||) which also adds a bit of tension.
There should not be any need for changing/preparing something except the trussrod. I´m playing 10s for a lot of years on my silo spec and had never any problems with the strings by using the trem.
Just be careful when its time to change your strings.I had put 10-46 on my silsp,and was in the process of removing an old set,and broke the end off the nut when removing the low E...so pay attention and you won*t have to renut your Balls!