I don't really see that it was much bother for them in terms of paperwork. As far as I saw, It amounted to them forwarding the customs paperwork for me to complete and return. The rest I handled directly with the customs agent appointed by DHL. They used the EORI to produce a VAT free invoice. I suppose there may have been some other work done between them and DHL but the delivery paperwork I received was not extensive.
It may also be related to the hassle of dealing with any issues with the cells. I'm still waiting for a resolution of my one cell with the post that fell off. They could have mitigated this specific issue by better checking the physical condition before letting them leave, but that won't help in all cases. For them to ship a single replacement will be quite high cost They are trying to get one supplied locally by fogstar instead, and asking me to provide the faulty cell back to fogstar in exchange. The problem is, all couriers list naked batteries as prohibited items. Perhaps that is the reference to dangerous goods? I expect the prohibition is there for consumers who may not label or package them safely, but business don't have that issue. It makes no sense otherwise, we can import cells directly from china without issues of being dangerous goods.
As it happens I decided to try drilling and tapping the terminal, because 32 cells have been sitting there unused for a month! 6mm did not work on torquing (pulled out) but 8mm is holding fine. I drilled a shallow 5mm hole and it appeared it went from aluminium to just touching copper. I don't know if that is a problem or not... but nothing leaked or exploded!
As far as the cells themselves go, they have been performing very well indeed. Staying very well balanced (~3mv) even without the active balancer. No issues with voltage drops. I can only recommend them so far, with the exception of the terminal falling off!! They have been a bargain for sure. I do continue to have issues with the BMS and my inverter using the SOC to control stop/start charging, which is just not accurate enough. I'm using voltage/lead acid mode instead which is working great.
Not that I can see me needing more, but If they will no longer export to the UK, even with EORI, I would definitely consider the drive to collect them, as long as they would still sell VAT free. I don't understand why fogstar are so expensive for these.