Hondata

I intend on selling my car very soon. However, I can't unlock the FlashPro from the vehicle or flash it back to stock because of the WEN pin error (The last FlashPro upload failed. Failure information: Code 0x22 Step 10 Address 0x000000). However, I don't have the time/tools necessary to troubleshoot this issue.

Would it be possible to send in my ECU and FlashPro in to unlock/flash back to stock?

Yes. Call for an RMA.

Alternatively put your ECU into another vehicle and unlock. The immobilizer does not need to be matched to do this.