Does beech sap foul membranes permanently

On the Facebook black walnut page, a fellow fairly new to RO said beech sap clogged the membranes so badly they had to be discarded. Quote from post:

"I was also experimenting with beech this year (10 trees under vacuum collection) because I've got TONS of beeches, so I bought an RO right off the bat. Which is good because my beech sap was a disappointing 0.2. Also if you think BW pectin is a pain, it can't touch beech. The RO handled the BW sap no problem, but the beech sap actually killed the membranes (expensive mistake). "

The manufacturer graciously went "halvsies" on replacement membranes.

This is especially surprising considering the low (0.2%) concentration. I RO'd bw first time this year with no issues. Anybody else ever see beech do this?

Sorghum demos 25 years
Sorghum and sugar cane syrups
Maple syrup demos 20 years
Maple, boxelder, black walnut, white walnut, black birch & sycamore
2 RO devices and a freezer for f-t
Developing low pressure cooker

This was the only individual I know of that has tried beech (he was using an RO Bucket). I personally spoke with him and we concluded that his issues had to be because of the Beech sap. On the bright side lots of people out there are processing walnut, myself included!

Somewhere I think I read you can get most of the pectin out of black walnut sap if you let it sit in almost freezing temps for a week and strain. Have not tried that but if it happens with beech, that might be the problem.

Beech sap is the dickens to collect if trees are away from 110 VAC. Distracted by maple and walnut this winter, I still managed to get about 3 gallons of .3 to .5% beech. Running a stronger than -20" Hg vacuum, I only got 1/5 gallon per hour per tap. Day before yesterday thawed it out, mixed it with 2 gallons some .8 something (likely maple) and RO'd to 3 quarts of 4.5%. Only quit because I was out of feed stock. Permeate was still dripping pretty well at that point so it RO'd no worse than birch despite similar glucose content. And vast majority of that concentrate came from blowing membranes and vacuuming the 5 mic filter.