Era Report 3145 on page 189 states "After 3101, only Clan Hell's Horses and Snow Raven maintained the use of ProtoMechs among the Inner Sphere Clans, and thus only Hell's Horses and Raven characters may choose the ProtoMech warrior sub-caste, ProtoMech life Modules or ProtoMech training."
Does this allow Horses and Raven characters to select the "ProtoMech (Advanced)" option under the Trueborn Sibko Life Module (ATOW, page 69) ?
In ATOW, the ProtoMech (Advanced) option is Blood Spirits only and so normally wouldn't be an option, but I was wondering if after 25-70 years the other Clans have upped their training at all?
