I don't know if SRT is dumb or smart though, and if it duplicate effort and copy files from the user partition into the SRT partition even though it's on the same SSD. I would think yes, but no big deal...
FYI, you set a volume to be accelerated and can not SRT an SSD. So there is no way to SRT a partition of an SSD and it will not attempt to cache data already on the usable area of the SSD.
The main problem I see with this plan is the overuse of the SRT'd area of the SSD which may cause premature failure since static data will be taking up certain areas not allowing the wear leveling to work properly. It's probably not that big of a concern with current SSDs, but it's the reason companies make cache specific SSDs that have much more aggressive over provisioning.