We have done this type of situation. We have told them that as a short term rental we are not licensed to rent for more than 28 days at a time. But they are welcome to do multiple 28 day stays. They are taking their chances on whether I will have availability after the first visit. But usually, after the first couple of weeks I have a sense of them and I might be willing to block the upcoming calendar until they are ready to book it.
I think these scammers target new listings. I haven’t seen them on my older existing listing, either.
This is misguided and a complete waste of time and resources. Having a guest do multiple 28 days stays has absolutley no effect on the laws that determine whether they become tenants or not. If guests become tenants after 28 days in your location then they become tenants after 28 days whether there’s a new booking or they leave and come back after a week or whatnot. You’re sorely underestimating how laws work.
99.9999% of the time it’s not going to become an issue anyway but you can’t circumvent the tenancy laws by doing multiple stays. In some places the tenancy laws literally mention this potential issue within the law (“28 days or more however enumerated”).