There's actually multiple walls here with multiple solutions... allowing PurchaseItem from the server api is just one of them.
- I need store item customdata to be copied over to the inventory item customdata on grant
- call a client.PurchaseItem that has a new parameter to copy over the customdata for me
- call a cloudscript that calls a new server.PurchaseItem and then copies over the customdata
- call a cloudscript that calls a new server.GetStoreItems and does all the purchase item stuff manually and copies over the customdata
the best hack I can figure out in the meantime:
- call a cloudscript that uses an http.request to call the client.PurchaseItem api followed by copying over the customdata