@NotATether:
I would put the change by itself in its own LN channel
So u mean like send the certain change funds with coin control to an established LN over swapping for example with integrated swapping in electrum.
His suggestion is that you take the change UTXO and send it (in full - not to create
even more change) to your own Lightning channel using a submarine swap provider such as
https://boltz.exchange/.
Avoid change is only possible with donation or an exact payment where in and out txes are equal or
Correct; you either send a UTXO to the destination in full, or you generate change. No way around that. Therefore, you either overpay (there are ways to only overpay slightly and still be private [1]) or generate change and need to decide what to do with it.
[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. When paying for something, you combine those to just about cover the requested amount. For example: You have 3x 0.001BTC, 2x 0.002BTC. When you buy something for 0.0029, you take one of each and pay 0.003
BTC.
@LoyceV:
I'm not sure what you mean.
I mean to create multi exchanges with an none KYC services like swapping to obfuscate the change funds.
Like Loyce, I don't understand what this means. Do you want to obfuscate change by exchanging it for Monero and exchanging it back, instead of mixing it or sending to a Lightning channel? What is a 'multi exchange'?