I mean to create multi exchanges with an none KYC services like swapping to obfuscate the change funds.
I'm still not sure what you mean. Can you make up an example?
Avoid change is only possible with donation or an exact payment where in and out txes are equal or
Or by carefully selecting the right input site, or by increasing the transaction fee a bit, or by carefully paying multiple addresses at once, or by changing the amount you're sending. The latter is often possible when you're topping up a service.
[1] One way to accomplish that is to be very diligent with coin control and have a wallet just filled with ChipMixer chips. Of different sizes.
This is the scenario in which the Electrum server you're using knows those addresses all belong to the same wallet. That may or may not be a problem.