"...I suspect maybe the lye beads are lighter than flakes, allowing the static clings to be seen more...."
Yep, that's right. Plastics tend to build up an electrical charge due to their chemical structure. Most things that are electrical insulators (like plastics) tend to do this. When the humidity is sufficiently low, the static buildup will be greater because there is no water vapor to allow the static charge to dissipate. Anything sufficiently light (human hair, NaOH bead) that has its own electrical charge (or electrically polarized structure) will be attracted to anything with an opposite charge.
"...it can be seen as a danger to us soapers and a liability to the companies that sell it..."
Selling NaOH to retail consumers is already a huge liability for a supplier because it's so hazardous, even without static cling. It's nearly impossible for some soap makers in other countries to buy NaOH at all, so we're lucky in that regard.
All I expect from my supplier is to provide NaOH in a sturdy, cost effective container that's suitable for shipping and long-term storage. I do not expect my supplier to also solve the problem of static cling. It's honestly a minor, intermittent problem that can and should be dealt with by the user. I can think of a number of solutions --
Use dryer sheets to reduce static cling.
Wipe down your work surfaces with a damp cloth to temporarily raise the humidity right before working with the dry NaOH.
Shake the lye in its tightly-capped container (with a finger over the cap for safety) for 10-20 seconds before opening it to help equalize the electrical charges between the plastic and the NaOH.
Do not soap when the room humidity is below, oh, maybe about 40%.
Make larger quantities of masterbatched lye solution when the humidity is sufficiently high to prevent static buildup, so you have lye solution to use rather than have to repeatedly measure dry NaOH.
Find a source for NaOH flakes, which are heavier and not as prone to static cling.
As far as using glass to store dry NaOH, I don't recommend it. If you want to get away from plastic, I'd advise using a stainless steel container for greater safety (stainless is not breakable) and doesn't create static cling (stainless is an electrical conductor.)
