he can repurpose the miner to mine on a pool account that does not belong to the owner of the miner.
They might as well just ask you to get lost and say you do not own any miners, thus, operating without being under a "legal umbrella" outside of your country is a huge risk, think about all the bad things that happened to those greedy folks who sent their miners thousands of miles away for cheap hosting, while many hosts were straight out scammers, some others were "smart" scammers, they would let your gear mine for say a month, and then tell you "The PSU was broken, you need to send a replacement or we can buy it for you locally to save you shipping time and cost", what choice do you have? pay them for the PSU, a few weeks later, the control board is dead, rinse and repeat.
Many countries have robust court systems, rule of law, and property rights. Ideally, Chinese miners would move their equipment to a country in which the owners could call the local police if millions of dollars worth of equipment were stolen from them.
If I were a Chinese miner with a farm with 20k miners, I might send enough supplies such as PSUs to support 20.5k miners and have failed equipment be sent back as it dies.
It's completely impossible to conduct such business without
1- Being at the site physically
or
2- Trusting the other person 100%
If you assume there is no risk of criminal prosecution for someone who steals your equipment, you are trusting the entity providing hosting unless you have exclusive access to the site. If the host employees can access the site, they could steal your equipment when you are not there. This is why it is ideal to have your equipment located in a country in which there are real risks to brazenly stealing expensive property.
Another issue is the repair services, large miners in China were offered on-site repair services by Bitmain and other major mining gear manufacturers, your gear stops mining? call Bitmain and they will send someone to fix it at the site, what do you do when you have 1000 gears that need fixing in El Salvador?
I think this was a major reason why so many mining farms were located in China. If the Chinese miners move their equipment to a similar location in a high enough concentration, companies like Bitmain may send support staff to that general area to help with things such as on-site repairs. Depending on the labor market, they may even move some of their manufacturing to that area.
I would point out that if a farm was moved to some country in which theft of the miners was not a concern, without the ability to quickly repair miners or replace PSUs, the utilization of the miners might fall to 80% or 90%, or maybe a little lower if broken equipment is held locally for longer than it might otherwise be. This might be compared to 95% or 98% that Chinese farms could get in the past, but it would also be compared to 0% that farms are getting now. If a farm can send 20k miners to a secure location, and over several months 5k of the miners go offline due to various issues, the owner still has revenue from 15k miners they would not otherwise have.