I have some CR 3110 CTs. They do not have internal TVS diodes.
They do not require shielding, but there may be codes that apply to the leads when used in various environments. The eChun and AcuCTs have leads rated for 300V and 80°C, which is stamped right on the wire and should comply with most codes when used inside an electrical box.
You probably are aware of this but FBO anyone else reading this, TVS diodes are not needed for the IoTaWatt to work properly. They are there to protect the CT against damage in the event it is unplugged from the IoTaWatt while the primary load is active.
I installed CTs in my panel years ago, before starting to import eChun or AccuCTs. As a result, I have an eclectic collection of CTs:
I’ve never bothered to change them under the “If it ain’t broke don’t fix it” rule. (I do have eChun CTs in several other installations). You can see that I use CR3110 CTs, but I did install TVS diodes into the cords so That I could unplug them (as I have over the years) with impunity.