We need to track the serial numbers of products. So, in product list we have a model (Cisco 1812, vendor, manufacturer...). We have 40  routers sold to different accounts. Twelve of them were bought for price x, and sold for y, 4 of them were bought for z and sold for k......and so on. If we inserted additional product field, that field can be edited only first time product is registered, but not when we atach that product to account. The only field that is editable is "Comment". If we register every single piece of sold product into products list that will be  a huge list.

Please, can you allow us to set additional field that is editable later for every specific piece of product for serial number location, tag number....

Btw, if Contact is the only one who send the request (not Account), why the product is associated to Acounts and not to Contacts? If ten identical PCs belong to same Account but different Contacts, how to distinguish them?