After some research by me and a little by other people in my alliance, it appears that there are no Medium structure rigs that effects the ME/TE of Capital Core Temperature Regulator (CCTR) production (I couldn’t verify L or XL rigs).
The standard sized Core Temperature Regulators are covered by the M-Set advanced component manufacturing rigs, but the capital ones are covered by neither the aforementioned rigs nor the M-set basic capital component manufacturing rigs. I’m a little surprised that CCTRs are not covered by one of these 2 rigs (e.g. the FTLs, used in all the same capital ship manufacturing, are covered by the M-Set Advanced Component Manufacturing rigs).
If this is not an accident or and assuming I didn’t miss the correct M-Set rig, I would implore CCP to assign CCTRs to one of these 2 rigs like the other new capital components, especially since these are used in every capital ship and now account for more than half of the manufacturing cost of most capital hulls.