The telegram group has all the information in the pinned post, which has been there since October last year, but they don't even bother to read. Even when mixing, there is a massage stating that minimum is 0.001 BTC and that the deposit address should only be used once.
True. All the information is there, unfortunately people learn best from their own mistakes (which is not a bad thing, though can be painful).
They usually come to the telegram support only after they made a mistake of sending less than minimum or sending to the phishing site or sending the result of mixing straight to centralized exchange.
Also not all of the mistakes are made because of lack of understanding of how the mixer works. Sometimes it's lack of understanding of how the blockchain or the cryptowallet or the exchange works. For instance, people sometimes send less than minimum because they don't realize that the wallet/exchange they use deducts the network fee from the specified amount. Therefore they send the minimum amount, but the mixer receives less and it confuses them. Such problems are out of our reach. Or do you disagree?
I think the only way to help users make less mistakes is better visual aids on the website, possibly bigger font for minimum amount. Brighter claimer to download and verify the letter of guarantee.