The Reliability of the Bitcoin Network Is More of a Bottleneck Than the Scalability of Bitcoin Block Space

The more inputs we added to the coin join, the lower the success rate was. And when we made some Tor optimizations, we could succeed to sign a coin join with every user at a much higher number of inputs. There are lots of ways to address all of these problems, but there's more practical limits to the size of the coin join other than the Bitcoin protocol. So we will not even try to attempt this anytime soon.