I doubt very much your average lawyer will even know what a mixer is.
If you think your lawyer doesn't have any idea of the FinTech laws, then you should probably change your lawyer. If you can't even afford a proper lawyer right now, then you have nothing to worry about.
If you aren't doing anything illegal and you are not mixing a significant amount of money, no one would bother you. The man-hours it takes to compile the evidence to prosecute a person is not worth the time, don't worry about it. That is unless you are doing something illegal and you definitely have things to worry about then.
Never mind mixer, the average IT lawyer doesn't know about crypto and how it affects legal responsibilities/risk. I say this with all due respect, and from the admittance of an IT lawyer I engage for work over the past couple of years. They're pretty great at tech, fintech, but decentralised tech (I know only Bitcoin really qualifies) is something they're only just coming to grips with.
MiCA provides much-needed clarity but it's national law (even in the EU) that's a challenge for them.
I always say, don't let your understanding be motivated by the fear of getting caught for doing something wrong. Be motivated that your personal freedoms and fundamental rights -- including money-related -- will always be under attack.