this is what i got from david today.
Wrenchguy
This information came from several sources, all older men who worked in the late 1800’s & early 1900’s in the timber/balloon building era. Two from the Fall River/New Bedford MA area and one from Maine. They each had their own name for them, “SHAKES PIN”, SHAKES WEDGE, SHAKES STOP & Wedge Wicks”, They all said that this was a learned technic, passed on from master to apprentice. It was explained to me that these pins help stop faming from drying to fast. They were use more in the hot summer months when framing was exposed to the sun for weeks or months at a time. Remember that nearly all framing and sheeting lumber at the time was “green” usually delivered to the job site the some day it was cut from the log. In balloon construction, a 2×4 that is nailed to the bottom plate at the foundation is also nailed to the top plate at the roof line. Sometimes these 2X4’s can be over 20 feet long or longer, with better than 60% moisture, standing on end, in the sun to dry and already fasten to other wet lumber. Like you I have not found any written verification for this, just hearing this from the old-timers that worked in this era. Hope this is helpful.