Sending broken TP back with custom rom still loaded- bad idea?

[Nat2fresh]

Heres my situation..

My screen stopped working sometime last week, i did a few soft resets and then a hard reset which only worsened the situation due the screen still not working and resulted in me totally locking myself out the phone. I couldn't get past the set up screen where you have to tap the screen and do screen alignment so i took the phone to verizon.. i was pretty sure they couldnt get it to work either, and i was hoping that they wouldnt be able to tell a custom rom was installed. They tried all their solutions but couldn't get past the set up screen either, so they decided to send me a new phone.

Now that i have the new phone, i wondering should i send in the old one at all with the custom rom still installed? Will they check that at whatever warehouse its going too?

In advance, Thnx for any advice.