I agree, BTC > XMR > BTC is a good choice because XMR is a privacy coin. Its anonymity is so good that it was delisted from Binance. Investors will always feel safe when using BTC > XMR > BTC services on Tengri.
I believe Ethereum has millions of users, the success of TornadoCash confirms this. It would be good if Tengri soon supports the ETH Mix-service through XMR, Tengri will have millions of potential users.
Yes, regulators find it hard to know the XMR based transactions, they have done their best but still they failed to know that how to break XMR's privacy, and that's why most reputed mixer use BTC to XMR and then again XMR to BTC to clear out the Bitcoin.
Yes, there are so many users who hold Ethereum and they love it as much as most of us love Bitcoin. It would be exciting to see the Tengri mixer to implementing ETH to XMR mixing functionality.
That depends on the requirements of the users whether they prefer privacy or not, if they do then it is not a hard task to acquire privacy so it doesn't really matter that much altcoin lovers will give more priority to this service. It's just a thought but the real functionality is what will attract them and make them love this feature. Till then we should wait.
Privacy lover will always prefer BTC over ETH because it's truly decentralized and no one controls it. While the case is a little bit different with ETH as it's a centralized coin. However, the popularity of ETH has made it the 2nd best choice of the investors and users after Bitcoin and thus having it on a mixer could be a game changer for the privacy lovers. ETH to XMR mixing functionality will fulfill the needs of the privacy lovers and I believe they'll love it.