Large letter weights can vary in weight paper letter, cardboard letter, box,
There's a bug with click and drop when it comes to weight.
Because of packaging weight can vary for same size items
Because item weight is 20g i.e ring, phone case,
Packaging envelope, box card box weight is 25g,
it can hold 3 items.
If you sell products 3 products the weight is now
over 100g bandwidth, because multiplied the packaging weight 3x.
Large letter weights can vary paper letter, cardboard letter, box,
In shipping rules there need to be able to set weight for the large letter packaging.
I hope that's helpful :)