Unless you buy your digital coins using cash, the exchanges have the identity of those who purchase and redeem coins/tokens.
From the documentation:
Taler is compatible with anti-money-laundering (AML) and know-your-customer (KYC) regulation, as well as data protection regulation (such as GDPR).
AML and KYC are all about removing anonymity. Merchants may not have the ability to correlate a purchase to you but the exchanges do; otherwise, they wouldn't be able to comply."Forgetting Your Customer" is *not* how you comply with "Know Your Customer".
Do you have any reference to how your blinding/unblinding supposedly works? Is it even mathematically possible to *insure* your identity is forgotten --- while still maintaining verifiable coin/transaction validity?
Without some such insurance, you're operating on blind trust and assumption. And you know what happens when you *assume* too much?
And in addition might have recorded serial numbers of the banknotes...
Except in very specific, pre-arranged circumstances (such as a ransom demand) they don't bother recording serial numbers --- simply because the info is quickly rendered obsolete and useless from the way cash is freely exchanged and "mixed" in the marketplace.
Cash is typically considered untraceable and is the ultimate physical form of anonymity. It neither requires nor provides any identity info. Gift cards purchased with cash are the ultimate form of digital anonymity. Neither of these conform to KYC.
The base objective of AML and KYC is to eliminate anonymity from transactions. Compliance is generally not possible otherwise.
Is is possible to trace back a gift card to the store that sold it? Maybe even the date and time? Then get the surveillance tape... If you pay with the same gift card more than once, all those transactions can be linked.