Yes
It can do checksum 
You can try for it 


 

Hi sir 
please order this one to solve your problem 
https://www.foxflash.co.uk/wholesale/foxflashr-otb-expansion-adapter.html

 

pls read the support list if have this
Let him checksum manually

That OTB1.0 expander has two very important functions for customers:
First, reduce the risk of brick ecu,
It can be said that there is basically zero risk in operating the ECU in OTB mode.
Second, it supports ecu tcu acm dcm offline mode operation, which is convenient for customers to mail ecu to merchants for operation.
  if no bench protocol , just have OBD , you customer want postal remap , so you have to use this OTB tune it , perfect solve it

Supported functions:

1: Dual-channel high-speed CAN

2: Three-way BOOT

3: Dual VCC power supply

4: GPT encryption and decryption function

5: Adaptive resistance

6: Adaptive CNF signal adjustment

Supported models and list
https://www.dfb-technology.com/driver-list.html
Log in to the browser at the above address and search for OTB to view the models and models that support OTB.
If the query mode cannot be displayed when opened, please clear the browser cache and reopen the website.
 

New features for extenders

Need not
Only the host needs to be connected with an obd cable
Just connect obd to otb expansion adapter

Connect the host computer to the OBD line, then the engine computer, gearbox computer and any supported module.
Just connect the can line or k line to the otb adapter
Then you can read and write at high speed, and you can also solve some OBD read and write error modules.

Please try for document inside the foxflash folder