You can not add Lot information (as well as anything else) to posted entries.
Lot/Serial info is not stored in ILE table, you would better don’t mess with these tables directly, as this can cause serious trouble.
added/ actually is, but for quick reference only - it’s not the MAIN place of tracing data /added
YES it is a bad solution (actually in this case it is not a solutioan at all) and Enduser should NEVER be allowed to do something in any Tables - their license doesn’t allow it physically, how do you imagine them to do things like this?
Secondly, it will have an adverse effect on Costing. Generally, in Business companies use Lot Numbers for 3 purposes: Tracking, Costing & Expiry.
If Costing gets messed up, there will be an Huge Impact on Finance. So, the result is Catostrophic.
Suggest your Client to Start with a new Item Numbers for those which Lot Numbers were missed out and Block the old Items.
2 Methods to Suggest:
You can sell out completely and block the Old Item and then start with the New Items.
You can do a negative adjustment to the Items without lot Numbers and make it to Zero and then do a positive adjustment by assigning a lot numbers to the New Item Numbers. But then you have to make sure on the Outstanding Orders, Shipped not Invoiced, received not Invoiced, Warehouse Transfers, Production Journals…etc. It’s quite a Tedious job.
I would suggest, follow the 1st method given your Scenario.