So since I offer Scrap for sale and all. And if they buy scrap, I want them to have the option to have it saved in their backpacks for unlimited time, since they paid for it. But I do not wanna keep other things in it.

Ive set "Clear BackPacks on Map-Wipe" to false.
Blacklisted raiding materials and ore things. Since I dont want them to transfer anything else besides Scrap until forever. Can you help me with this or program an add-on onto that. Thank you