It is not the same as home vs coffee shop vs office. It about working for entirely different country and company that has nothing to do with US. I don't how from moral point of view working for company in UK can be harmful to US workforce, because thats what original immigration law is about - don't take away jobs from locals before you get a permit.
Say I would own a business in Narnia for what I perform certain duties, possible to fulfill from anywhere in the world, and marry US citizen - do I have to throw it away for one year just so that potentially I wouldn't break unclear rule which appears to be forgiven anyways even if you DID work for entity in US illegally?
These types of misleading posts are all over on the internet and are usually from people who have no first hand experience in remote work under these circumstances. I would advise this topic to be only discussed amongst people who have dealt with similar situations. Everyone else just muddies the water with their 2ct.
Having said all that if anyone is in the spot of choosing between K1 or CR1 with similar remote work possibility - CR1 would be my choice any day out of the week. K1 is built so that the potential immigrant would be as miserable as possible and be on hold for up to 2 years since all this covid situation. You cannot drive, open a bank account, cross internal CBP without stress, etc for longer than you think you'd be okay with it. So it's better life experience to live abroad for both parties till the CR1 is approved.