I too could have ticked the don't care as my tug has a 3500 kg limit, but I didn't want the van over it's limit.
Mine has actually been over twice,once when loaded & it came out as way over the limit (100kg) so the next time I literally stripped the van back to factory & re weighed it, then weighed EVERYTHING before they went back in & recorded it on a spreadsheet.
It is surprising how all the little bits & pieces add up, so with the spreadsheet I can now easily prioritise what comes & what stays home or travels in the car to stay under the limit by simply moving the weight from one column to the next.