SP-D’s “tiny peak” on the downslope of the N term peak is more pronounced when measured on grayscale value in this trimer, and is very low on the valley when four trimers are joined in a dodecamer.  Arroyo et al, 2020, Fig 2A right image, bar=80nm for the trimer shown below.  Purple bar is just below the peak plotted for this trimer using ImageJ.