I think you'd probably get away with subsidising your living costs from crypto here in the UK, possibly to the extend of thousands of pounds a month if you're careful. Where you're likely to come up with issues is on larger scale purchases like for example buying property where there is legal requirement for you to declare the source of your funds. In those cases, you're either going to need to 'wash' the money or just declare it as taxable income.
Yes large purchases would be scrutinized and have no problem with that. The everyday living expenses would be the smart way to use it using a crypto card. Also depends where you live because you could withdraw into another tax jurisdiction and then move it.