Are registers and VPT-shallow identical?

[qlOvQlp]

I found that the operation of adding registers in the VIT model is identical in implementation to the VPT-shallow approach in Visual Prompt Tuning https://link.springer.com/10.1007/978-3-031-19827-4_41. Are registers and VPT-shallow identical? Can the register operation also be used as a fine-tuning method to improve the performance of tasks downstream of the model?