The other direction is just get a wallet that supports a real airtag. Because my wallet is so important to me, the name brand airtag, with UWB-enhanced findability, is worth swapping out my wallet rather than getting a sub-par credit-card find my compatible device. nb, I came to this conclusion after getting an aftermarket credit card device and found it lacking.
I have almost an identical wallet; I really considered using the card form factor but I would miss the precision find too much.