I personally don't give a shit from where I acquired my BTC. I personally don't give a shit about any gov of taxman that knows how much BTC I bought from x exchange. Why? Because I never go back to fiat and I would simply ask the taxman "who the fuck are you to ask me about my own money".
But you have to realize that there's no such thing as "KYC bitcoin", or tainted. It is tainted identity, it is your identity that is KYC, your personal data that is shared, sold, used WITHOUT YOUR CONSENT. That is the real danger of KYC.
Buying things with BTC is not illegal or immoral or something bad. So stop blame yourself for that or feel guilty with something. Just try to avoid KYC to protect your personal data. That's all.
Also read my guides. I wrote several about how to use LN as a "cleaning machine". And use the 3 levels of stash: hodl, cache, spend.