Bitcoin isn't anonymous. The ledger is public and your wallet has to be linked to you only once for every purchase you've done to be entirely attributed to you.
This can even happen years after you've deleted the wallet key and moved on to a new wallet.
Sorry, forgot to mention mixing multiple times, using multiple Electrum wallets, in multiple Whonix VMs via Tor, using different mixing services, etc, etc, etc.
So sure, all that Mirimir spends is linked. But nothing is linked to my other personas, or to me in meatspace.
Edit: Bitcoin Fog was used to mix thousands of Bitcoin from at least two thefts. In 2013 from Sheep Marketplace, and in 2015 from Bter. And as far as I know, none of that was ever traced.
That's just one of the mixers that I used. So I'm not at all worried.
Just use the official Monero wallet, the only difference is that you'll need to visit xmr.to to enter the Bitcoin address you want to pay to instead of doing it in-app.
This can even happen years after you've deleted the wallet key and moved on to a new wallet.