Which options do i have to set to eliminate change utxos

[skyerjoe]

Hello

I made a few sucessfull coinjoins with wasabi then i found an article from Thibaud Marceal
on which he describes the options to avoid survellance over the change output. And he also describes the Elemination Feature from Wasabi but i havent found any options to activate the "change-avoidance feature"

so where i have to set these options to eliminate the change output.

best regards

[MarnixCroes]

change and toxic change are two different concepts.
toxic change basically means a coinjoin output which can still be linked.
change is just from a normal user transaction.

In Wasabi, basically all private coins (coins with anonymity score) are not toxic change. So you don't have to worry about that when your coins are private.
You can then send these coins to someone and have change on the transaction, it's normal but could even still be avoided by using the change avoidance. see step 6, the Preview Transaction image: https://docs.wasabiwallet.io/using-wasabi/Send.html#how-to-send-bitcoin-step-by-step

(if there is change, you will always see the info message Transaction creates change. But it can be that a suggestion to remove change is not available. Sometimes it is available to send a bit more or less so you will not get change from the transaction (and you don't have to coinjoin it again later))

[skyerjoe]

So, if i have to pay some coins with the possibilty avoding a change the best bet is to use it for an fruther conjoin or.

Thibaud says in his article that ur able to use the change coins in a new coinjoin for free. How does this work

best regards

[MarnixCroes]

if you did sent a transaction with change, then you should (and Wasabi automatically will) coinjoin that change coin.
It's "free" because these coins don't pay coordinator fee, because you used private coins and coins from one hop tx don't pay coordination fees.
they do still pay mining fees of course.

Note, that there is a minimum for a coin to able to coinjoin. 0.00005000 BTC minimum, which is currently even higher.

If you made a payment and the change is 0.001 BTC then Wasabi will automatically remix that coin.
If you made a payment and the change is 0.00001000 BTC then it will not automatically remix that coin, you'd have to consolidate it with another coin, by making a transaction yourself, so the coin amount is more than the minimum for coinjoin ("free" remix doesn't apply then anymore).

So for small change amounts, using the change avoidance (and sending a bit more) makes sense for economic point of view as well, not only privacy wise.

[skyerjoe]

What will happen if i overpay with an whole coin an bitcoin bill for example an vpn supscription , never tried it before cause i thought im loosing my coins if i do so.

[MarnixCroes]

i thought im loosing my coins if i do so.

yes you are, that's why you only want to do it for a couple cents or dollar.
That is taken into account for the suggestions as well, it will not show big differences.

What will happen if i overpay with an whole coin an bitcoin bill for example an vpn supscription

if you pay for a service, overpaying is usually not a problem. underpaying can cause issues.