Thanks for sharing. 1.1% fumarate is not too bad. Lower stem is not as potent as the midsection as I understand it.I did a small potency test on 50g of Noid bridgesii. 0.55g yield fumerate. dissapointing. This was a lower-in-the-stem cutting, aged for 6 months, no dark stress. Shows that bridges aren't always the most mescaline.
And yes, there is a large variability.
Extracting and propagating the spicer as cacti with precise mescaline measurements is a very worthwhile enterprise. I think it will make cacti in captivity more consistent/potent over the next decades.