Bamboo wadding material for gambeson?

Hello,
I would like to make make cloth protectors with linen outside and 100% bamboo wadding inside. One of them would be a gambeson, so heat regulation is the top priority, over everything else.

I am from Europe, so far I did not have much luck finding proper material inside the continent. One of the best candidates are this one:

https://billowfabrics.co.uk/products/simply-bamboo-100-bamboo-wadding?variant=40986721026159

It sounds great price/value/thickness ratio-wise, but I noticed a line in the description:
"100% Bamboo with poly scrim for stability"

After researching what poly scrim means, I realized, it does have a polyester layer on one of its side.

My question is, will this polyester layer render the material useless heat regulation-wise? I will use it in high summer temperatures, and want to avoid anything which would affect it negatively.

If yes, what should I use? I might layer further linen canvas layers (220g/m2), which would be kinda the same in price, but would be much more work, and would not be as pleasing visually.

Another idea of mine is to use heavy jute textile for the inside layers, which are thicker than the linen one, cheaper, but are 100% natural still. I just do not know, how will itt behave if it gets wet.

With which solution should I go? Will the bamboo wadding material be good regardless the poly scrim layer? I plan to use 3-5 layers. Or should I pick something else? Can this poly scrim even be removed at home?

EDIT:
I found this 100% cotton one, without poly scrim, but I read in other posts inside this group, that it might be really hot during summer. Which one would be better?
https://morrisworks.co.uk/products/heirloom-natural-100-cotton-wadding-7-5-metre-roll.html#/