You are using the terms "partnership" and "cooperation" to describe a relationship between a customer and a business, which is misleading. There are companies whose business model involves aggregating reports of coins being stolen, and zkSNACKs buys those reports in order to avoid accepting those stolen coins. If zkSNACKs were to buy a McDonald's hamburger, that does not mean "zkSNACKs is partnering with McDonald's".
Wasabi or zkSNACKs aren't private customers, though. They are businesses using the services of other business entities (blockchain analysis) whose version of the truth and estimation affects their own operations. In other words, you accept the decision of the blockchain analysis company's views regarding the cleanliness of my UTXOs. My participation in your coinjoins depends on the truth the blockchain analysis firm serves to you. I call that a partnership and cooperation. You are free to use any other terms you like.
As I already pointed out with my McDonald's example, purchasing a product from a business does not constitute a "partnership". Here is the list of zkSNACKs' partners:
You keep talking about open-source, where can we see these rules publicly? According to whose criteria will certain UTXOs be added to whatever list is being used to determine naughtiness of coins?
Since the coordinator code is all open source, you get to decide your own criteria yourself.
Here's another idea if we're about to utilize layers: exchange BTC for XMR and XMR for BTC a little while later. Leaves no traces, much better than Wasabi + lightning altogether. You could then coinjoin the bitcoin, just to minimize the blockchain connection with the previous owner.
This doesn't provide you additional privacy since you leave a trace at step 1 when you send your non private BTC to your XMR counterparty.