Pccb Brand (And Others) Storage Safety

for reference, my collection are coins worth from $20ish - $100ish. doesn't warrant TPG slabbing but I want something nicer than 2x2s with a little more room for writing/notes.
I like to handle my coins once in a while (100-200 years old, circulated and not much worry about de-valuing them via handling) so 2x2's do tend to be a pain.

I've thought about using SAFLIPS but don't like the way the coins can move around. Ive seen all the other generic acrylic slabs but don't like the way the typical foam inserts "pillow" around the edges of the coin.

SO, it seems every company claims to be archival safe, but are you confident storing your collection based on these claims? how do you know what they are really made of? (especially no-name bulk supplies from retailers)

PCCB (claims to be PMMA plastic with inert inserts, but made in China, which I assume most of the other name brands are as well) has some really nicely styled holders but I am nervous as they are only (so far) sold on ali-express or ebay (orient direct).

would you bet your collection (with any name brand, including TPGs) solely based on the word of the manufacturer and/or the float/burn test?

has there been a study and/or is there any published data regarding chemical compositions of the materials, covering all the name brand suppliers? or would that be overkill (chemical testing)?

here are some of the PCCB items I am referring to, if they were available by someone like lighthouse I would be a little more confident and probably jump all over it.









as always, opinions and feedback greatly appreciated